When you file your proper tax returns, the IRS will eventually notify your former girlfriend that you were not eligible to be claimed as a dependent, and she will be required to repay any part of her tax refund that was due to claiming you as a dependent, along with interest and possibly a late fee. For 2018 and 2019, the amount is a straight $500. For 2017 and earlier, we cannot estimate the amount she would owe without more specific information from her tax return.
