When Carter was six, she began to hate wearing skirts and dresses and having her hair in pigtails. She couldn't explain why because she didn't know why, but... she knew that she didn't like it, at all, and was quite vocal about it - even despite the insistence that she was cute or pretty when all dressed up. But, she was never forced to wear what she didn't want, and overall, it seemed like something she would grow out of. That it was just a phase.
But, as she grew older, her discomfort only grew, and she knew it wasn't a phase. She hated being called Miss by JARVIS or anyone else. Hated being referred to as a girl or young/little lady. She still hated wearing skirts and dresses, and refused to do anything with her hair aside from leaving it down or pulling it into a ponytail. Still, it was hardly an issue with how she dressed, and she just... simply bit her tongue when she was uncomfortable. If someone called her miss or young/little lady, she said nothing. She still didn't understand why it bothered her as much as it did, and... she didn't want to cause problems. She caused enough problems as it was.
It wasn't until she was fifteen did Carter begin to realize she wasn't a girl. She didn't say anything to anyone, unsure if she was making it up and scared of how her family would react - still hurting from the homophobia she faced in school. But... it made sense. It explained why she hated wearing dresses and skirts, and why she hated being seen as a girly girl. She knew she wasn't a boy, but... at the time, thought those were her only two options. Thinking herself as a boy didn't feel good, but... she convinced herself that, maybe, she was one, because she knew she wasn't a girl. But she still couldn't get herself to bring it up to Tony or anyone else, and a part of her began to grow miserable. She wasn't happy with herself and how she looked, and began to wear neutral and darker colors, if not just black, and baggier clothing to hide her body. Her hair was long, but she hid her desire to cut it short, and kept it tucked beneath her jackets, or down and hiding her face. Her change in appearance sometimes confused others and made her look like a boy, and she did her best to convince herself that was what she was, despite the way her stomach seemed to drop and her heart seemed to hurt.
When she moved out and went to college, Carter began to experiment with her appearance. She felt a freedom she didn't have at home, but was still scared to go too far with it. She continued to wear neutral and dark colors and baggier clothing, but got a pixie cut in a desperate attempt to feel comfortable (although quickly came to her hair), and did her best to come across as androgynous as she could. She was too scared to try to use different pronouns or introduce herself as male, despite still telling herself that's what she was. She was able to hide she was female for the most part, but still struggled with how much she hated her appearance. She hated her body and hated her voice, but couldn't figure out what would make her happy.
Stephanie was the first person she was open with about her struggles, but... her girlfriend was dismissive. She only seemed to get angry when Carter tried to explain to her how she felt, so Carter stopped talking about it. But her feelings of dysphoria only worsened while she was with Stephanie, because it was something her girlfriend refused to drop. She chastised Carter for wearing baggy clothing and tried pushing her to look more feminine, and told her she was embarrassing her, because she was her girlfriend, not her boyfriend. Carter failed to see it being a reason why Stephanie refused to be open about their relationship, and failed to see how toxic it was, and she tried to look more feminine to try and make Stephanie happy, even though she wasn't. She was miserable, more so than ever, and there were days when she would catch sight of herself in the mirror and get physically sick. She hated herself and hated her body, and hated she couldn't just accept she was a girl and be done with it, because she knew she wasn't a boy, either. And with her mind already frayed from losing Maya and nearly losing Tony (again), and being in an abusive relationship with no support on campus and her pushing what support she had with her father away... Carter was at her lowest. She refused to look at herself in the mirror and fell back to wearing baggy clothing and layers to hide her figure, and drew further and further into herself. Her ragged mental state and constant anxiety left her struggling to eat, and as she lost weight, her dysphoria worsened. She felt stuck and alone, and did her best to suffer in silence to make things better for those around her.
After Carter joined uni, however, things began to change. She became fast friends with Mikey, and, while she didn't say anything about her gender, she got the courage to admit her sexuality to him, and he supported her. He encouraged her to go with him to the uni's queer center, and after hesitating, she agreed, and was introduced to a number of resources she didn't know existed. She discovered she identified more as bisexual than homosexual, and... soon discovered that she wasn't just limited to calling herself a woman or man. But she was still scared to explore that option - still hurting from Stephanie's abuse and still struggling with her dysphoria. She continued to try and tell herself she was a woman, because she knew for certain she wasn't a man, and that she couldn't be trans because of that. She was fine with the pronouns she was using, and that... she just needed to suck it up when it came to honorifics. And then she met Cody, who was proudly nonbinary, and Carter finally got the courage she needed to dig a little deeper when it came to herself.
With a support system in her new friends, she grew to like the label genderqueer - that there was a word that accurately described how she felt by identifying with neither female or male. She tried out different pronouns and found she still preferred she/her, and began to grow more comfortable asking not to be referred to with feminine honorifics. She didn't mind being called her father's daughter, which she didn't quite understand, but... she was growing more and more comfortable with herself and her body, and after divulging it to her therapist, she got the courage to come out to her father as well. She began to joke that she was working towards a PhD just so she could be called Doctor instead of Miss, and was clearly happier than she had been before.
Her style changed again, and while she still heavily favored wearing pants over skirts or dresses, she began to wear shirts her size, instead of trying to hide beneath baggy clothing. Although, she saved her oversized leather jacket just because she found it comfortable, instead of trying to hide herself. She began to experiment with makeup on occasion with Cody, although preferred to go light if she did decide to wear it., and kept her hair at neck's length. She didn't miss having it long, but she didn't like keeping it too short, either. And, although it took longer for her to feel comfortable seeing herself in the mirror again, with therapy and encouragement, she was able to do just that without feeling ill. She could look at herself and feel content, and no longer spent days crying because of her appearance. No longer struggled to eat because of how nauseous she'd feel just by how she looked. She was comfortable with herself, and she was happy. She knew not everyone would understand how she felt or her identity in general, but... she didn't care. She was willing to explain if they wanted to know, and as long as they respected her, she didn't expect them to understand it. If they accepted her for who she was and didn't try to pressure her to change into someone she wasn't, she was fine. She was still happy.
But, even with all of her progress, there are days Carter still struggles with dysphoria. It's not as extreme as it had been, but... every now and then, when her mind is in a bad place, she'll question herself. Question whether or not she's faking it with how comfortable she is with feminine titles and appearing feminine. She does her best to not focus on those thoughts, and to remind herself she is genderqueer regardless of what she uses or dresses as. That she could be happy with herself, and that it didn't matter what anyone else thought of her. She had family and friends who supported her, and that was enough.