Probably not, unless she is a student.
In order to claim a child as a dependent, they either have to be a Full Time student if they are over 18 years old and under 24 or they have to earn less than $5,050. If these do not apply, even if you are providing for her living expenses, you cannot claim her as a dependent.
To claim someone as a Qualifying Relative, they must be:
- Your child ( including step children, adoptive children and foster children) or a descendent of them
- Your sibling (including half siblings) or a child of your sibling or a sibling-in-law
- Your parent or grandparents, including step parents and in laws
- Any other person that lived with you for the entire tax year
- Not a qualifying child of another taxpayer
- Someone that you provided over half of their support for during the tax year
- Has less than $5,050 in income (not counting social security)
The following criteria must be met to claim someone as a qualifying child:
- Your child (including adopted and foster children), your sibling, or a descendent of any of them.
- Age 18 or younger at the end of the tax year OR under 24 (and younger than you and your spouse) if they are a full-time student
- Lived with you for more than 6 months during the tax year
- They did not provide more than half of their own support (social security does not count)
- They did not file a joint return, unless it was to claim a refund