My Daughter Needs Prayer

I have an 18 year old daughter who desperately needs prayer. She has been involved with drugs since around the age of 14. I was very young when I had her, therefore my parents have raised her. My father is in denial where she is concerned. My mother knows what is going on, but I think she is "tired" of fighting. She is too old (legally) for me to make her do anything. She was raised up in church and she knows the Lord. I have to believe she will find her way back. Sometimes I feel like our relationship is beyond repair. I want to help her, but she wants no part of it. Please pray that God will touch her heart and turn her around. I fear everyday what the next phone call will bring. Please pray for her...Her name is Chelsea....