Man she realy dont care about your problems. She just want a guy near her. Only problem is most guys are evasive like you and younger guys are even worse. In the end girl things its her fault and guys think shes not good enought. Remember at 15 girls tryed tos seduce me but I ignored her not because I didnt liked her but because was thinking shes joking. After while she ended up with 19 year old fella. Cant blame her for that.
So its basicaly up to you to decide. Girls at that age dont need much, you could keep her around even without sex.
Doubt kills more dreams than failure ever will