I've been seeing this girl who is very cautious to escalate. She's put up a lot of barriers from the start, starting with not letting me kiss her the first night I met her even after sexy dancing for a couple hours.
I passed those hurdles by taking my time and trying to build attraction, rapport, kino escalation etc. Now after several times hanging out, we've been kissing and rubbing through clothes, and she recently slept over in my bed after a late night makeout session, but she still won't let my hands in her pants. She says she's turned on but says things like, "this kind of passion should wait...until later."
I'm not sure if she's just inexperienced or has trust issues.
I'm sure most people here would suggest simply forget her and move on to someone easier, but I somewhat enjoy the challenge and I also see her as potential relationship material.
I know that getting her to the next level will require more in-person comfort building, sexual escalation, etc. However, I also want to send text messages that will help speed things along via behavior shaping if possible. I sent a text like, "I have a feeling that when that fiery side of you gets fully unleashed, it'll be worth the wait

" and she responded like, "hehehe, no need to rush too quickly

"
Any ideas how I might be able to work through those barriers faster?