it's not aiding and abetting if the parents dont press charges. the only thing illegal the kids would be doing is running away, usually from an abusive situation. if the kid doesnt do anything else illegal, the only possible negative legal outcome would be that if he is reported as a runaway, and is picked up by the cops, he'll be held untill his parents/the school picks them up. if the kid had help, the parents can potentially charge kidnapping, but the chances of that would be slim to none, as there would not be any case. the kid would come looking for help out of his own free will, and we would not be holding him against his will (unlike the program).
of course there are legal loopholes through which you could potentially be prosecuted, any self-respecting lawyer would be able to get a case like this dropped in 2 seconds flat. (by self-respecting i mean not state appointed)
just make sure you dont give kids any drugs, have sex with them, or help them with any illegal activity, actually make sure that one of the terms of you helping them is if they abstain from all illegal or even questionable activity themselves, with or without you. By helping kids, I mean strictly provide food, a roof over their head, some clean clothes, medical treatment, emotional support, and help with negatiating with the parents to pull the kid out, or help the kid get in touch with other family members who take take him in instead.