Age of Majority: Sister at 29 with 5 Kids Want to Adopt 17year Old Sister

My question involves juvenile law in the State of: I am 29 with 5 kids my 17 year old sister want move with me her dad died when she was 12 mom at 4 she been leaveing with my aunt since are dad past she now want move with me but my aunt's say if we try the state could take her from us don't see how can she move out with out going court at 17 ty

Age of Majority: Sister at 29 with 5 Kids Want to Adopt 17year Old Sister