The income limit does not include social security benefits. However, if her benefits result in your providing less than half of her total support, that would prevent you from claiming her as a dependent. Here are the requirements to claim a qualifying relative dependent:
1. The person cannot be your qualifying child or the qualifying child of any other taxpayer. A child is not the qualifying child of any other taxpayer if the child's parent (or any other person for whom the child is defined as a qualifying child) is not required to file an income tax return or files an income tax return only to get a refund on income tax withheld.
2. The person either (a) must be related to you or (b) must live with you all year as a member of your household.
3. The person's gross taxable income for the year must be less than $4,200 in 2019. This excludes social security benefits.
4. You must provide more than half of the person's total support for the year. You must include social security benefits in determining this.
5. The person must be a U.S. citizen, U.S. resident alien, U.S. national, or a resident of Canada or Mexico.
