Can't stop her.
Whichever tax return is accepted by the IRS first will get the kid.....at least at the start.
If other spouse files first, and falsely claims the kid, then you will have to paper-file thru the mail, and eventually, the IRS will mail both parties asking them to prove their claim. Keep any records about child that might prove the child lived with you. School records, Dr visits/bills, mail/emails between you and spouse...anything showing you had the child.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
