mepal & others:
That is the idea of a “community” school, that accepts everyone from the area who is frum and willing to follow the rules. Perhaps this is what is needed in Brooklyn (and I thought Prospect Park was somewhat like that, but I seem to be wrong).
Is there no school other than BYOBP within lets say, half an hour’s bus drive that would accept these girls? (parental preferences aside, I think they have lost their right to choose if they are unwilling or unable to pay for it). If not, you have a situation similar to that in Lakewood & (I feel) the Rabbonim of the community should get involved to force the schools to accept these girls (if needed).