wow, you're kinda caught between a rock and a hard place. Either way, there's a possibility that you'll get hurt. Either, a) you date her and maybe she dumps you and you don't get to be with the woman you have feelings for or maybe you have a wonderful relationship, or b) you don't even bother to try being in a relationship with her and you still don't get to be with the woman you have feelings for. At least with A, there's the possibility of having it work out, just go into it knowing that you might get hurt, but at the end of the day, it's her job to figure herself out, not yours, so if she's willing, by all means go for it.

I'm really tired as I'm writing this, so if it doesn't make sense, sorry. Send me a message if you want to talk.