Generally speaking, To be claimed as a qualifying child, the person must meet all of the four criteria as shown below:
1. Relationship Test
The qualifying child must be your child, step child, adopted child, foster child, brother or sister, or a descendant of one of these (for example, a grandchild or nephew).
2. Residence Test
The qualifying child must have the same residence as you do for more than half the year. The IRS has stated that "the qualifying child must live with you for more than half the year. More than half a year means, at minimum, six months and one day."
3. Age Test
The qualifying child must be either of the following;
- under age 19 at the end of the year,
- under age 24 and a be a full-time student for at least five months out of the year,
- be of any age and be totally & permanently disabled.
4. Support Test
The new rules state that the qualifying child must not provide more than half of his or her own support. This is different from the old rules. Under the old rules, the taxpayer had to provide over half the support for the child. This subtle change makes it "easier for families relying on public assistance, charity, and gifts from family members to claim a dependent."
I think you fail the test based on age of your qualifying child that is on 3) above and possibly 4).