You've got alot on your plate here. It's obvious you really care & are trying hard to make her feel a part of the family. She probably feels pretty bounced aroung at this point.
Because of safety of your other children I would feel need to get child services involved again. It's one thing to be patient with her but not at cost of wellbeing of your other children.

This forum doesn't get alot of reply's. Maybe try Relationships & Communication one, it seems to get alot of traffic.

Only wishing you the best.