I would suggest also, that even though your daughter has already filed, that you figure your taxes with her as your dependent under HOH status, and then figure your taxes without her. Secondly, refigure your daughter's return claiming herself and not claiming herself to see what her taxes are. Thirdly, do the math and compare how it comes out best for both of you. If it is better that you claim her on your return, and she not claim herself, then file an amended return for her, take her off as an exemption, you claim her. I have done this many times as a tax preparer. Not sure if I made it clear, but your goal is to minimize your total tax liability, which would increase any tax refund for both of you. as the father, you can always give your daughter part of your refund to make up what the daughter gave up so you could claim her. Being a mathematician, it is matter of juggling numbers.
