My question involves a child custody case from the State of: Indiana
My ex-wife and I have a six year old daughter. I have remarried and my wife has two daughters that are essentially the same age as my daughter. We married two and a half years ago. During the time from our marriage to recently my ex-wife was receptive to agreeing to have the children on the same custodial/noncustodial holiday schedule. By Indiana guidelines it meant that my ex-wife, who has living custody of our daughter agreed to follow the noncustodial holiday schedule and I followed the custodial holiday schedule. That allowed my wife and I to have the three girls together for holidays and most weekends.
Recently, my ex-wife has decided that she no longer wants to follow that arrangement. She wants the custodial holidays and for me to have the noncustodial holidays.
It seems logical to me that this decision by my ex-wife is detrimental to our daughter. Our daughter has developed a great relationship with her stepsisters and the other way around. They look forward to seeing each other and are sad when they don't.
Is there some material that I can use to demonstrate that this decision is not in our daughters best interest? Are there some studies, reports, legal precedence.

