It’s $2500 per child based on that child’s Qualified Education Expenses, not just a combo of the parent paying $8000 in tuition and then getting the credit for 2 kids (I wish, as I pay more for one child and don’t get the AOTC for the other). For two kids, you fill in two schedules, for three kids, three schedules.
Of course, the OP otherwise has to qualify for the AOTC and have enough tax liability to use the credit as only part of it is ‘refundable’.