My daughter has a 17 year old friend that was on probation. Her mother did not want her to be with her boyfriend and yet she was and got caught. Her mother has since called the Probation officer and there is a warrant out for her now. I am unsure as to what her mother turned her in for doing at this point. There has been a hearing set for next month in which I believe she is trying to get her daughter on home confinement.
Her mother is this girls problem, unfortunately, for many reasons that I will not address.
My question is do I have any grounds or hopes of possibly getting them to let her stay with me at least until September? Otherwise I feel she will run.

Legally - no, not if the mother doesn't want to allow it. As for hopes - you can hope her mother allows it. Other than that, you have no legal standing in any of this.

Thank you Steve