Q. Is it actually allowable to do that since she didn't receive the 1098-T?
A. Yes. That's why the exception question is there, in TT.
A form 1098-T was made a requirement for the education credits a couple of years ago. However, if you qualify for an exception, you may still claim the AOC, without a 1098-T. If you attended an eligible institution, you most likely qualify for an exception.
“However, a taxpayer may claim one of these education
benefits if the student doesn’t receive a Form 1098-T because
the student’s educational institution isn’t required to send a
Form 1098-T to the student under existing rules (for example, if
the student is a nonresident alien, has qualified education
expenses paid entirely with scholarships, or has qualified
education expenses paid under a formal billing arrangement). If a
student’s educational institution isn’t required to provide a Form
1098-T to the student, a taxpayer may claim one of these
education benefits without a Form 1098-T if the taxpayer
otherwise qualifies, can demonstrate that the taxpayer (or a
dependent) was enrolled at an eligible educational institution,
and can substantiate the payment of qualified tuition and related
expenses.” https://www.irs.gov/pub/irs-pdf/f8917.pdf
