@emilymcbroom-136 and to prevent this from occuring again in 2023, suggest requesting a PIN from the IRS.
With a PIN, only the person who knows the PIN (presumably only you) can efile with the children's SSNs. Anyone else attempting to efile using those SSNs will be rejected.
and if the other person tries to paper file and include your children's SSNs. the IRS will review that tax return very, very closely before approving it since there will be no PIN included with the tax return and the IRS knows there should have been one.
https://www.irs.gov/identity-theft-fraud-scams/get-an-identity-protection-pin
