Hmm, I'm no expert on this, and anything I say comes with the warning that I'm white, but I'd be more likely to read if that way if the character's crush was because of some of the stereotypes about people of African ancestry, or darker skinned people in general. There's a certain use of language that would trigger some alarms for me. Moving like a jungle cat, skin like chocolate. All that kind of stuff.
And this could be done in a way that makes it clear that's what's happening and examines it, of course, in which case it wouldn't be offensive but illustrative.
I think focusing on things about the woman's personality and so on might make it feel more like a more sympathetic crush/attraction. A lot of the time when I've liked someone in that way, it's not just their appearance (actually, with me, it never is), but also things I imagine (at least) that we have in common. So emphasizing some of those things would make the crush seem more deep and authentic, at least insofar as crushes are ever deep and authentic.
