You can legally demand whatever your final order allows you to demand.  If you have a final custody order which allows either of you to pick whatever sitters you would like, without notice or consultation to the other parent, then no, you don't have a legal right to the info. You can ask for it, but your ex isn't required to give it to you.If the order requires your ex to give this info and your ex refuses, then you have the right to demand it and seek contempt if your ex refuses. If you don't have any orders in place, then you don't have an immediate remedy.... but you can petition the court for orders to address this issue.