You cannot claim the child care credit for payments to your daughter if you can claim her as a dependent. It doesn't matter whether you actually do claim her. What matters is whether you can claim her. Go to the following link on the IRS web site to determine whether you can claim your daughter as a dependent. If she's still in college and living in your home you probably can claim her.
Whom May I Claim as a Dependent?
Also note that you can only claim credit for child care expenses for children under 13. Expenses for the older child are no longer eligible for the credit starting the day the child turns 13, even in the middle of the year. If you are paying for care for both children, you will have to figure out how much of the cost to allocate to each child.
