when i first met my boyfriend we hit it off pretty good. after about six months or so he started getting in with the wrong crowd a doing hard drugs, he dissapeared for three days without letting anyone know what was going on and he started comming late to pick me up for dates,ect... everyone that i talked to told me that i should make him choose, and i almost did. but i realized that at the time if i had made him choose that he would have choose it over me. so instead of making him choose i let him know that i was always there for him. i knew tht all i could do was let him know that i was there for him. and by sticking with him i eventually helped him quit. it took a couple months but he finally did it. looking back on that situation he tells me that if it hadn't been for my unwavering support that he wouldn't have ever stopped. and i am so glad that i didn't listen to everyone's advice. because over two years later we are still together and very much in love.
i don't know the particulars of your relationship or how you feel towards each other. i believe in soul mates, that one person that you are ment to spend eternity with. and weather she is or not i cant say, but what i can say is that even if she isn't she has a part to play in your life good or bad.