Your student has to be your dependent, for you to claim her 1098-t for a tuition credit. First, be sure you've entered her info in the personal info section.
If you enter the wrong student, you'll have to delete all the info and start over. Go through the entire education interview until you reach a screen titled "Your Education Expenses Summary". Click delete next to the student's name. You'll then get the "Your Education Expenses Summary" screen again. Click the "Add a student" button.