In terms of tax law, the parent with whom the child spent the most nights during the year, (considered to be the custodial parent by the IRS) has the right to claim the child. That parent can give the right to claim the child to the other parent, by giving them an 8332 form. Even then, though, the noncustodial parent cannot claim Head of Household, the earned Income credit, or the Child Care Credit based on this child. Those benefits do not transfer with the 8332. If you disagree with her claiming the child and she's doing it according to tax law, you would have to take it up with your divorce attorney.
