Need some advice with my stepdaughter.

I am married to a wonderful man and we have custody of our three kids, one mine and two his. Their mother is still in the picture, but does more harm than good, in my opinion. She has two adult children who are both unable to function within society. We obtained custody last year after she signed them over during a custody battle. We had lawyers involved for the kids who substantiated neglect. It's a heartbreaking situation for them.Since they have come to live with us full time, the youngest had begun to form some clingy maladaptive behaviors. She tells us that she loves us repeatedly. Yesterday, she told me 54 times in six hours. She will sit outside our door and knock every ten minutes. This starts before we are even out of bed in the morning. She can't stand to be in a room and not touching or engaging someone. She tries to get attention by refusing foods she likes, being contrary, crying all the time. She cries at least ten times a day to get attention. Sometimes it's just to ask for water despite not needing permission to get water.She is eight and regressing terribly in her autonomy. This is where things get tricky. Mom is mentally ill. Not sure of a diagnosis, but would guess borderline. Since we have taken custody of the kids, she has started helicopter parenting the youngest. She is now in the bathroom when she showers. She sleeps with her. She is not allowing her to grow and she is reinforcing the attention seeking behavior because it feeds into making biomom feel good about herself.Here comes the wtf do we do to fix this? I have some power. I've seen what this women does raising kids and it's not pretty. I know having no relationship with the mother would be harmful to them, but this stuff can't be happening either. I'm open to suggestion and advice. Thanks in advance. via /r/Parenting http://ift.tt/2vyas5x