Pre-Series
Connie's life prior to the series has yet to be explored too deeply. she was born in a rather strict family, her parents often in control of most of what she did in her life. She had met Steven Universe, and became her first true friend.
Season 1
After not hearing from Steven after a while, she went to the Crystal Temple and wanted to check in on him, only to find much of the group affected by Poison Joke. She was caught up on the situation: Steven going off to Equestria and meeting Fulgurite, just before the Spider Monster arrived. During the fight, she was given her Portal Key, and she quickly figured out how it worked, using it to go to Equestria. She appeared in Ponyville and found Steven with the Mane Six, Amethyst, and Lapis Lazuli, and quickly got them to head back to Beach City, saving the rest of the Crystal Gems.
During one trip later with her mother, Connie found Pearl after she became discorded, and she quickly tried to get her to look more presentable, and basically get her back to normal. Unfortunately this resulted in Connie getting hit by her. Upon arriving home, Connie got in a bit of trouble by Priyanka Maheswaran and Doug Maheswaran. Distraught, she ended up going back to Equestria, and appeared over in the Mirror Pool, which she used to summon Connie II for a companion. She remained away from how for the next following days, bonding with her doppelganger and keeping out of contact with her parents. After a talk with Maud Pie, she decides to return home.
Later on, she and her family ended up encountering Sombra, who proceeded to capture her to be used as a sort of bait for the Gems. She at first tried not to cooperate, but ended up getting her feet broken when Sombra stomped on them. The wounds weren't too bad, her still able to walk and run when she was rescued, though she couldn't do much following after.
Season 2
Preparation Arc
Connie called Steven sometime after the Sombra incident, catching up with him on things, getting both of her feet in casts boots when Steven introduced her to Diopside. During the visit, and after fighting off some seagulls, she was given the idea to be put under some swordsmanship training under Pearl, and then later Kyra. She got Pearl to do so, explaining that she wanted to be there for Steven and she felt hopeless with Sombra prior to this. Her training however has given her the questionable ideology that she was worth nothing, and Steven was worth everything, something she quickly got corrected by Steven himself. She continued under training from then on, but with a better ideology in mind.
Homeworld Arrival Arc
She had recovered fully as time went by, and able to see them all off once the Galactic Ray was finished, getting a message from Steven a month after he left.
Season 4
During the celebration of Lapis Lazuli's anniversary, Connie had ended up accidentally fusing with Steven, forming Stevonnie for the first time. This was something Connie ended up very happy for, despite things going south at the RAVE. After a secondary fusion though, she went home and found that Flint told her parents about their Fusion. Connie tried to get them to think that it was alright, though not too successful on it and almost got forbidden from even seeing Steven again. She had to fuse with Steven later on though when another Gem Monster attacked her family, and afterwards was allowed to see Steven again.
After Sapphire was taken, Connie was told to take part, Flint saying that she was a vital piece to their plan and that they needed her to go, making this her first true Gem mission. She was one of the "offerings" for the Human Zoo, and she ended up with Steven and the Mane Six. She had to wait it out until later when Team B of the Crystal Gems arrived and got them free, only to be captured again by White Diamond herself. She managed to get herself out once they got to the throne room, and when the duel was called, she, Steven, and Amethyst fuse into Earthstone. She was allowed to go with everyone else.
Season 5
Cluster Arc
As work on the Gem Drill was being made, Connie found out about Amethyst and Steven's monster hunting mission, and decided that she wanted to help out. She helped out in their hunt for the Gem Tortoise and Tongue Monster, and going with the others back to Darastrix. Her parents allowed her to go on these missions, and wanted documentation of each one during this trip in particular, and fused with Steven to form Stevonnie in order to fight off Starlight Glimmer.
She went with them later on to check out the Strawberry Battlefield, only to be teleported away by Acid and Cyanide. She found out about The Cluster thanks to Blue Diamond later on, but before she could go back, they ended up finding out where Malachite was. She and her friends went off to Mask Island, and she formed Earthstone again in order to heal her. She returned with the others to confront the other Gems, though couldn't do much about the Cluster as the drill was already gone.
Serpent Arc
After the Cluster had been handled, she went home and started to relax a bit. During a casual visit, she came across Kevin again, not seeing him since their encounter at the RAVE. She wanted to get even with him, and upon hearing about the Autumn Country Drive, she decided to take part. She decided to use Stevonnie as age requirements are needed, and Smoky Quartz was too big for the car.
After the Beach City Flooding occurred, she helped out by allowing Sadie Miller and Lars Barriga a place of stay after some convincing to her parents.
After a bit, she went with Steven, Amethyst, Pinkie Pie and Rainbow Dash to Griffonstone in order to find Acid and Cyanide. She went with Amethyst, though during the search she found Amethyst was not enjoying it, finding out of her jealousy with her and accusation of her taking Steven all for herself. She ended up arguing with Amethyst until Acid and Cyanide appear and paralyze her. She was sent into the Abysmal Abyss, still unable to move. She then revealed that she wanted to train Stevonnie because she was far weaker compared to Smoky Quartz, and that it was her who was jealous, albeit less negatively. She was saved and brought back to the temple, only to be captured by Grootslang for ransom. she and Amethyst manage to fuse into Ammie, and defeated Grootslang (albeit accidentally).
Season 6
She had recovered after her encounter with Grootslang, and after getting the greenlight, she brought Connie II back to Earth, and introduced her to the Crystal Gems. She went with Connie II for Harmony Day, but during her tour, she stumbled onto her mother in town. Connie helped explain who Connie II was and got the situation calmed down.
During the investigation on the Pink Diamond case, specifically with the conclusion that Rose Quartz didn't shatter pink, Connie ended up facing Diamond's Dog. She tried to get Steven to fight with her, just to find him surrendering himself. She tried to fight the beast, but got her arm broken to such a degree that it was planned to be surgically removed and replaced with a prosthetic arm, just to find it healed on its own despite everything. While glad she was fine, she felt betrayed and "hurt" by Steven, and decided to cut off communication and leave with Lion. She wasn't sure how to feel on the situation, going as far as to Ocean Town. she came across Connie II, and later Sabina, before deciding to go back and talk to him, just to find him not home.
She later appears in Beach City when she came across White Diamond, but was unable to do much of anything and got her mind erased of their existence. She was found by Spike and Rutile Twins, but was completely freaked out as she didn't properly remember them. She found Lars later on after he got knocked out, and when Blue Diamond's Gem Object activated, she regained her memories and immediately tried to get the others back after being shown the Temple. She tried to head to the Warp Pad, only to find out from Connie II that it no longer worked. She helped her team get off of Earth and onto the White Diamond Space Station, but during her time there she ended up getting her lower torso crushed by White Diamond, making her unable to walk before they could all escape.
Season 7
She remained with the rest of the Gems as they were stranded on the Jungle Moon, remaining as Stevonnie as a means to help her walk. She gets back to Earth once the other diamonds find them on the planet.
Season 8
White Diamond Arc
When she learns about Steven's unexpected "vacation" out into space, she is snuck on aboard inside Steven's large backpack, saying that she would've gone with him anyway even if he never told her, as such keeping their promise to always go everywhere together. At first Connie was kept hidden away from the others until the second stop on Farid, but she was allowed to roam freely afterwards.
Grogar Arc
During the Era 3 Festival, she was found out by Grogar and, in order to save Steven, she threw herself in the way of one of Grogar's blasts, becoming corrupted thanks to her half-Gem DNA, turning her into a "Corrupted Gem". In this state, she is taken hostage by Grogar and put under arrest in the Supreme Kindergarten's prisonhold. Throughout much of this arc she tries her best to reconcile with Grogar, as she is picked out by him as his bride for an upcoming wedding for him. She placed herself under intense personal training since then, and by the time she was rescued by Steven, she became strong enough to crack the Diamond Palace walls. she and Steven form Stevonnie to fight Grogar, but she remains behind after Steven runs away.
My Little Universe II
It is revealed that Connie got cured of her corrupted state thanks to Nephrite and has since then tried to aid the others in building Little Homeworld. Before Spinel made her move on Earth, she discovers Steven returning home and happily welcomes him back. After a brief talk and learning about Grogar's involvement in all of this thanks to Tempest Shadow, she and Steven form Stevonnie to confront him again.
After the rejuvenated Gems started to reform, Connie was unwittingly thought by Pearl to be her master, being referred to as "Ms. Maheswaran". Throughout much of the arc, while helping the others out she tries her best to give Pearl more freedom and have some of her memories return to her, as Pearl won't leave her alone. The most she ever got out of her to leave her be was accidentally getting involved with Autumn Blaze, Pearl believing that Connie had perished in the fire and triggering her emotional memories to swell.
She joins the Harmony Gems in both the following court session to get Discord and White Diamond's magic back, and the final main battle between them and Grogar's Army. Just before the main battle in the Realm of Corners, she joins the original Crystal Gems and Elements of Harmony to take out the weapons located on Homeworld, but got caught by Grogar and forced into fighting him. She and the others tragically got shattered during the fight. She and the rest were revived and reformed afterwards within the Supreme Kindergarten and join to stop Grogar's army from leaving Homeworld. During the third part of the end fight, she joins Spinel and Steven in going into Sumu's main core to stop Sumu, saying that she will always be by Steven's side no matter what things are. With Spinel's help, she helps Steven reunite with Pink Steven.