Foster Care with PCHA for 15 yr old bi-polar Granddaughter?

After having my Granddaughter, Camille, for most of her life, my health is now forcing me to consider foster care for her. This is breaking my heart as I love her so but I am just not able to control her any more. She is rebellious & just refuses to do anything I ask. She recently just took my car (I was in bed due to health), then had an accident & left the scene. She is also sexually active with 3 boys already & has admitted to doing drugs. She also failed school this yr after being an A-B student before. She sees a psychiatrist & all his recommendations as well as from family & friends is that I need to put her somewhere where she will be supervised & learn that she must be respectful to authority. I have heard about the Presbyterian Children's Homes but have not yet heard any comments about it--whether good or bad. I know that I must do something especially since school is out & I know that each day is going to be a battle. Unfortunately, Camille gets extremely angry when she doesn't get her way & she leaves any time she wants. She is much larger than I am now so physically, I can't restrain her & what hurts the most is that she has no respect for me & in fact, just mocks me usually. I would appreciate any recommendations about PCHA or any other program. I love her regardless & it's hard for me to even think of letting her go but I know that would be the best thing to do for her. I would love for her to be gone for a few month or even a yr or two..I just feel that unless I intervene now, she just miight stay on the wrong path which could untimately destroy her life. She is bi-polar which is very difficult to deal with but she is on medication & when I make sure she takes it, it works extremely well. It is just getting her to take it. I do appreciate all of your help..more than I can say. God bless you all. Cammi