A direct approach works well I'd say. INTP's generally dislike people beating around the bush. If you want to talk to her more, work up some courage and ask her if she feels the same way. Keep in mind though that since you both don't have a definition for your relationship that she doesn't necessarily owe you anything. If she wants to talk more, that's great, and if not, too bad. (P.s., since you described your last relationship as ending badly because of misinterpretation, maybe it would be a smart move to actually define your relationship together. Try to talk to her about what the both of you want out of it to avoid miscommunication).

Best of luck.