My daughter will be flying from Greece to Florence where our family will be staying. Does anyone know commuter airlines that fly this route?
I don't see any "commuter" airlines that make this route. I do see two of the inexpensive carriers that do fly from Athens to Milan (Easyjet and Agean Air). Your daughter would then have to take the train to Florence. Finally, Swiss Air will fly to Florence from Athens (via Zurich) for $452. Alitalia will make a similar flight via Rome for $300. Or, cheaper yet, fly Alitalia to Rome from Athens for $163, take the Leonardo Express train into Rome Termini and then take the Eurostar to Florence (1hr. 40min) for $57. Just a few thoughts.
Aegean air also flies Athens-Rome...from there, take a train. Aegean;s lowest seems to be about 128 Euro, but you can input your specific dates to see.