Again ... if she filed as a dependent and you correctly claimed her then you will do NOTHING. It is possible that you BOTH filed correctly and ... there was another person that claimed the child ... probably by mistake or someone did it on purpose ( hello ID fraud). SO if you are correct then you will do nothing at this time.
From the link I gave you :
What you need to do
- Compare the social security numbers from your notice with the social security card for each dependent or qualifying child you listed on your tax return.
- Review the rules for claiming each dependent or qualifying child. After reviewing the rules:
- If you find you’re entitled to claim the dependent, you don’t need to write or send anything to us.
- If you find you listed someone who doesn't qualify as your dependent or qualifying child, you must correct your return by filing a Form 1040X, Amended U.S. Individual Income Tax Return. The instructions for this form will guide you through the steps to correct your return. Mail your amended return to the IRS service center shown in the instructions.
