don't worry about going too easy if she says she can handle it. if she says something then you can adjust, or you can check in with her to make sure. it might be a little awkward sometimes but if she's fine with things, don't worry about it. it's actually better for learning for her anyways.
unfortunately, I've rolled with some female students in my class, and because of the fact that people tend to go too easy on them, they only develop the skills at that level, so when we spar at a level greater than 40 percent, they tend to have a tougher time, because they haven't had many people go harder in sparring with them, than that, and as such, don't have their skill level up to the point of being able to handle it.
as awkward as it may be, it's actually better for her that you don't go easy on them unless she specifically say "you're going to hard", that way she can learn to deal with it. also, being careful in and of itself can also help you learn control as well.. but yeah. if she doesn't have a problem, then don't sweat it.