A form 8332 is ONLY used between the custodial and non custodial parents and not between you and your mom to let her claim the grandkids on her return. For her to claim the grandkids they must be qualified dependents on her return and you could not have claimed them. AND even if you did waive the right to claim the kids to the non custodial parent using a form 8332 it is the non custodial parent that needs to file the form 8332 that you signed to give the the right to claim those kids.
WHO CAN I CLAIM AS A DEPENDENT?
You can claim a child, relative, friend, fiance (etc.) as a dependent on your 2021 taxes as long as they meet the following requirements:
Qualifying child
•They are related to you.
•They cannot be claimed as a dependent by someone else.
•They are a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
•They are not filing a joint return with their spouse
•They live with you for more than half the year (exceptions apply).
•They are under the age of 19 (or 24 for full-time students).
Qualifying relative
•They don't have to be related to you (despite the name).
•They cannot be claimed as a dependent by someone else.
•They are a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
•They are not filing a joint return with their spouse.
•They lived with you the entire year.
•They made less than $4350 (not counting Social Security)
•You provided more than half of their financial support. More info
When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them.
you may want to use a tax pro. if you're the one legally entitled to claim your kids your mother claimed them improperly. she could have serious tax problems.
You cannot just "allow" someone to claim your kids. The rules must be followed.