My child is 28 years old. She made $2900 last year. She files her own tax return and is on medicaid and is a student. Can I claim her as a dependent?

[xmasbaby0]

If you paid for over half her support she can be claimed as a "qualified relative" and you can get the $500 credit for other dependents.   If she is a student you may also be able to get the Lifetime Learning Credit.   On her own tax return she must say in MY INFO that she can be claimed as someone else's dependent.