Enterprise in FL is great for one-way car rentals. Would she be renting a car anyway? If so just rent at MIA and return to MCO. The drive is boring but not horrible.
If she doesn't need the car... I can do a one-way, same-day rental tomorrow for $60
Did she buy a round trip ticket? Meaning, are you in the same boat for the return? If so, just leave the flights alone, rent the car, and have a longer airport commute on each end.