As side issue - it great you want to help resolve but set a deadline in own head for improvement. My friend just been dealing with this issue and like you, she was working with child and there has been improvement. But just this week, she have two other client give notice because they fed up with it.

Already you say that having this child in your care mean you not able to take other children due to the attention he needing but try not forget that ultimately, this is a business. As grateful as parent are for times we all go over and above, that not pay the mortgage.