Can me as the dad or can my 17 year old daughter file a lawsuit against a stepmom--- my ex?

Hello this question is from a very dedicated dad who has custody of my 15 year old son and 17 year old daughter. We live in Iowa and I've had custody of them the last 6 years. The problem, My ex who I have another daughter with who is almost two picked up moved into another mans house about 10 miles away. I... show more Hello this question is from a very dedicated dad who has custody of my 15 year old son and 17 year old daughter. We live in Iowa and I've had custody of them the last 6 years.
The problem,
My ex who I have another daughter with who is almost two picked up moved into another mans house about 10 miles away. I have joint custody ,she has primary, I pay my childsupport,I was getting my daughter 2 days one week 3 the next.This has went on for 2 months now. My ex has been away from me for about 4 months. For some reason she won't answer her phone now or let me see my daughter on my days.
Yes I have a lawyer, but he doesn't seem to be as helpful as he should be.
Can I file a lawsuit on behalf of my other two kids for the emotional abuse my ex is putting them through by not letting us see my daughter,,thier sister?
Does a brother and sister have any rights?
any help on this would be greatly appreciated.
A dedicated DAD
12 answers 12