You absolutely need to speak a L to get your rights. I know that each state is different but when I separated in 1998, my kids were 2 and 5. I was the primary caregiver in the family home and was told that I could not move them more than one hour from the familial home. At the time I wanted to live closer to family for support. It is possible they will tell her that she can't move across country, and it will not be coming from you.
