Technically, yes, it's erotic transference and while it's normal in the context of therapy (meaning that it's understandable why such things happen in the context of therapy), this is not something I would recommend people to work with. I am yet to see any case when this thing was resolved successfully meaning that the client benefited from it.

I don't think your T will freak out if you tell her, but I also don't think it'd benefit you to tell her. So, I understand why you wouldn't want this to go beyond the point it is now. I wouldn't either.