The notice said "from another taxpayer" which may NOT be her ... so if your return and her return are both correct you have nothing to amend.
What this notice is about
We sent you this notice because we received a tax return from another taxpayer claiming a dependent or qualifying child with the same social security number as a dependent or qualifying child listed on your tax return. The last four digits of the social security number for each dependent or qualifying child we’re concerned about is shown on the notice for your review.
