"a couple days away from May 1st"
If it was a couple of days before May 1, she does not qualify as your "Qualifying Child" dependent**, the 5 month rule was not met. A couple of days after, she does meet the rule.
You only need the 1098-T to claim the tuition credit, not the dependency. Even then, you can probably claim an exception. Many schools have stopped mailing the 1098-T. The student has to retrieve it fro the school web site.
**There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, student status, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit. If she does not meet the QC test, she can also not be your standard dependent because her income is too high (>$4150)
