Transfem obikin au ramblings, by popular and indirect demand of one single person. I'm very happy to have an excuse to talk about it ^_^
So. My beautiful au where everything is the same as in canon, except Obi-Wan transitions at some point between meeting Satine and the events of phantom menace. She thought about it prior to meeting Satine too, and in their time together when Satine who only ever liked women up to this point, made joking remarks about that, causing some revelations. It's meant to be pretty light-hearted and since I really like the headcanon about Stewjoni people being dualsex I think the medical transition wasn't like, that complicated of an ordeal for Obi-Wan. I don't know how that would work. alien biology. She's happy and thriving by the time she and Anakin meet.
Anakin I think would have a very conflicting relationship with womanhood. Since sexual slavery on Tatooine seems to mostly affect women, I think Shmi would teach him to look after the girls he's friends with since an early age, and while Anakin thinks Qui-Gon is going to train him this doesn't really come up, but with Obi-Wan it's a whole *thing*. She's so beautiful and charming, and he knows she's competent, but he doesn't know how to *not* worry about something happening to her, both because of his upbringing and Qui-Gon’s recent death. Oh, and the mommy issues, of course. The mommy issues would be worse. He gets into fights with other padawans who make comments towards his master and is protective of her on both combat and diplomatic missions when someone is overtly nice to her. Obi-Wan is obviously unhappy about that, but once they talk it out and she understands the protectiveness is caused by the environment Anakin had to grow up in, they both compromise with each other to make the other more comfortable. It does get somewhat better with age, and it's not like Anakin doesn't know that his master can take care of herself, but he can't help worrying anyway.
At some point pretty early on after someone on a mission talks down to Obi-Wan and makes some misogynistic comments, she later jokes to Anakin that sometimes it's almost as if their job would've been easier if she stayed living as a man and Anakin is like huh? And after he gets a gender lecture he's like wow you can just do that. He doesn't really get why anyone would want to be a woman though, because that's Dangerous and that's what gets you sold to Bad People (aka something that's been drilled into her throughout all of her childhood and is one of her biggest hang-ups in accepting she's trans even after many years).
I imagine sometimes in his teens Anakin gets the biggest crush on Obi-Wan that everybody around him is aware of, and that's when he gets told that while she isn't particularly interested in anyone, everyone in the temple is pretty sure she's only into women so even IF she'd ever able to stop seeing him as a kid and her student, he still doesn't have a chance. And that doesn't sit right with him for reasons he can't quite get yet. Because, surely Obi-Wan would *like* him, no matter who he is. Or isn't.
Anyway, I think the final full realization is tied to something stupid during the clone wars, like Obi-Wan calling him a good boy after a mission, Anakin saying he isn't a boy anymore, which leads to Obi-Wan calling him a good girl. She gets so hard she almost passes out and leaves to have a gender crisis in the nearby tent and rant at Rex about it all. To continue the chain reaction, Rex of course goes wait? you can do that? why did no one ever tell me? I am making all of them into women. look out.