@Bigtonyd
That's not a tax question; it's a legal question. There's nothing in the tax code that addressees your question. It's an interpretation of the wording in the document.
But, be advised that the issue of emancipation enters the picture when the child reaches emancipation age for her state. An emancipated person is not longer in anybody's "custody". But, the mother can continue to claim the child as a qualifying child, for tax purposes, because the child still resides with her. But, the father not only needs the mother's permission (just verbal), he needs to meet the dependent support and income test, as well.
