Has she flown DL using a passport before? If so it is likely stored in system as "verified." Thus no need to show it before domestic flight.
However if it is not verified, then 100% for sure they will ask to see it before boarding SAV-ATL.
The only option other than sending, going to local airport DL ticket counter. Show them the passport, so it can be noted in her reservation as verified by a DL agent.