I have been folllowing along and sorry, but I think she found herself with someone pouting and tried to put some fun in it (you said she was trying to keep it as is until she moved out). I agree that a needle may have not been the best device, but she was just "poking" at you, trying to get you out of your grump. She wasn't trying to stab you or anything (I don't think). Sounds like you all used to have the "hey that chick was cute"/ "dang that guy was hot" and now you are both hurt and going off on every little comment/playful act.

I think that she realizes how "bad" she was and is trying to change and as that may be a little too late for you, I think that you blew this situation out of proportion.