Tripmom,
I infer your AGI is above the limit for claiming AOC for your dependents. You can, indeed, not claim a dependent and have the difference between their total qualified educational expenses and that portion of them paid with the 529, i.e. tuition and books mostly, used by the student to claim any nonrefundable portion of their credit. Be sure to apportion as much as possible of the 529 distribution towards the room and board and related expenses. (See IRS publication 970 https://www.irs.gov/pub/irs-pdf/p970.pdf ) for that info.) Then see if that decreases the student's tax more than it increase your own. If so, rinse and repeat.
