if my friend above is right and she is immature, forget about her, she's just wasting ur precious time.
but if she is not and u really like to fuck that bitch....
next time she gives u an IOI or come near to you to talk or something, escalate and kino her, engage her..........
if she does not allow you to escalate, punish her and give IOD's - a lot of them.
the most effective way to shit test her and if she is really into you and you want to make her uncomfrtable, hook up with another girl and that too in front of your target.
this should definitely turn on her evolutionary jealous switch....if she does not respond to this, just leave her, u still got the girl u made out with !!
its all win win..