Depends. Are we talking about kinky as in fetishes or kinky as in she just has a high sex drive/libido? People confuse the two sometimes (not saying that you are just trying to make sure we are on the same page). I don't think she'll have any odd kinks or fetishes, but I could believe that she might hide a high sex drive.
Jill similar to Bella hides certain sides of herself; just nowhere near as much. Aside from the incident with the MC's hand/arm while sleeping; hinting on at least some subconscious level it is on her mind. When talking to her at times she apologizes for saying certain things or laughing at things a "woman of her stature" shouldn't. I bring all of this up to say that... whatever training and lessons she's received fail to hide her normal personality at times which slips through the cracks. Not to mention other conversations in the bed before falling asleep with her that night of the fight. The "rich girl" thing isn't part of her natural self. So when we do finally open that sexual box...
it could very well be Pandora's box when it comes to sex with Jill. Especially if she's been bottling it up because of the reasons I've mentioned earlier.
I for one hope that that's the case, because I want to see just how hot Jill can really get. My MC is going to work that thing on that exquisite mattress until we fall through the wooden floors of that mansion!
R.I.P. bed, Let's go JILL!!!