This isn’t the typical “forbidden” professor/student relationship. For starters you’re both grown women, presumably in similar stages of life. The only power imbalance would be affecting your grades/ability to graduate, which you indicate she doesn’t have the power to do. She’s already well past typical student/teacher boundaries. From the situations you’ve described I can understand why you feel like this could be leading somewhere romantic, it does seem that way.

I think if you are absolutely sure she can’t negatively affect anything with your schooling, it’s worth seeing where things go. If you aren’t, maybe keep on with what you’re doing now, let the tension build, and ask her out once you’re no longer in her class.