You've missed to many signs throu the yrs.I dont want blame you but where were you all these yrs, why did't you teach her the deen, the selfrespect, the xaya and how a muslim girl should be?Do you know her friends and what kinda of pple she hang out with? why did't you send her to a muslim school and tought her at young age?
Her school and education should be the last thing to worry about huuno, ta madaxa ka saar.
Sending her back home ALONE to a country she never seen, to a langauge she never heard, to pple she never met is a bad idea but my advice to you is to take the whole family back home and put ur trust in Allah swt.Al risiq mina allah.Ur children are more important then all the mony in the world and you will be standing infront of Allah swt and asked for it for all ur childrens pathes and all their sins will be on you.So pack ur bags and save ur children and may Allah guide her to the right path.It's not easy to raise teenagers in the west and with all the hormons in their body they cant think stright.Most of them are confused and dont know who they're thats why they start imtate other to find themself.The environment we liv in is full of shadaadin, the TV is full of naked pple and every corner we walk there are pple on top of eachother so this become normal for all children.Ilaahy ha ku sahlo sis.
