Print and mail your return claiming both children for the custodial parent child tax benefits which include HOH filing status, EITC and child and dependent care credit.
Advise your ex that you are filing the correct way and suggest that she amend her return to indicate the child did not live with her more than half the year. If she doesn't amend her return, you will both get letters from the IRS later in the year requesting documentation to prove what you claimed on your tax returns. .
