A person you are not related to by blood or marriage can be your dependent if all these statements are true:
1. They lived in your home for the entire year.
2. You provided more than half their total financial support.
3. Their taxable income was less than $4150.
(They also have to be a US citizen or US resident alien.)
For support, you have to consider support the person pays for themself, as well as support provided by others (ex-spouse, church, other family members, SNAP benefits, section 8 benefits, etc.) You have to pay more than half her total support.
They would be an "other" dependent and would qualify for the $500 "other dependent" tax credit.
