She needs to go to MY INFO, click her name and go through the screens to the question that asks if she can be claimed as someone else's dependent. She needs to say YES.
She can seek a refund of tax withheld from her paychecks---the amounts in boxes 2 or 17 of her W-2. She will not get back anything for Social Security or Medicare that was withheld.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**