Q. Can my daughter be claimed by my ex-husbands girlfriend?
A. Simple answer: No.
Because she is not related, a dependent must live with her all year and that can't be possible since the child lives with you +/- half the year.
Even if the child did live with her all year, she could not claim full benefits (EIC, HoH, Child Tax credit) because the child is not related.
If she's getting a substantial refund, she's most likely filing an erroneous tax return. You should be the one claiming the child, since the ex does not work.
