Only the child under age 17 is eligible for the child tax credit (up to $2000 depending on your other income and taxes.). At age 17 and older, the children are eligible for a $500 dependent credit only. Make sure you indicated the children lived with you all year, and make they are listed with their correct social security number and that you check the box that the SSN is "valid for work" even if they are not currently working.
