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In their current divorce decree, I am guessing that it states that he provides insurance. If so, then he CAN do this. She of course can put them on their insurance as well, and she will have overlapping coverages.
By default, the paying parent also provides insurance. That is why I am guessing that by default the decree states this above. However, she has the right - along with the child support modification within the same case - to ask for a modification about the insurance and that the Court shift the burden to her. The Court may agree if it feels that it is in the best interest of the child.
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