Tumblr ate the first part of this, so I’m missing a bit of context, but from this part, it seems like you’re an otherwise straight lady who’s got a crush on a girl?
That’s pretty damn normal, especially for women. There’s some scientific evidence suggesting that women’s sexual orientations tend to be a lot more fluid than men’s, meaning that even a straight-identified woman may experience attractions to women from time to time.
Anyway, if she’s into it, and you’re into it, feel free to go for it! You don’t need to change your sexual label unless you want to, so don’t worry too much about starting to identify as bi or whatever else you’re considering.