it's probably going to be an age thing, but my first thought, and what i really hope it is, is that she's trans. not holding my breath, tho
I'm all for trans representation, but I don't think there's really a version of that that doesn't make Xiaoen problematic as hell?. She looks at the ID, immediately abandons all plans to go see Xingyuan, and apparently has a full on freakout about perversion. There are two possibilities. 1) She was talking about Xingyuan, or 2) she was talking about herself.
If it's 1, that's a super transphobic response. I mean, people fuck up and get better, but it'd definitely hurt my opinion of her. If it's 2, she's excited by it, which is skirting on fetishization, which is its own kind of problem? Either way, it changes the dynamic of the situation a LOT and would make me lose a lot of sympathy for Xiaoen.
Basically, without that, this is a light fluffy misunderstanding to be cleared up with a pinch of drama and maybe some backstory. With it, it's a serious character flaw that a character has to grow past. There are other reasons I don't think it's likely, but this is why I would outright hope against it.