We highly recommend going to the Acropolis. There are many restaurants nearby where you can see the Acropolis lit up at night.
For small towns, we recommend visiting Chania and Rethymno. There are many options for restaurants and shopping in both, however, rethymno has an old castle. For beaches, we recommend Elafonisi, Balos, and (of course) Fodele. For hiking, we recommend the Samaria Gorge. For historical sites, we recommend Knossos.
There are many islands in Greece with spectacular views, so you can't go wrong. Here are some islands we recommend: Santorini, Mykonos, Corfu, Naxos, Rhodes, Paros, Milos, Hydra, and Spetzes. We recommend looking into ferries that can take you from one island to another. They will have day and/or overnight trip options.
Sophie's mom is happy to help with recommendations. Please reach out to her via email: musemom4@gmail.com Let her know what you are interested in, such as beach, hiking, history, golf, etc. This will help her narrow down her recommendations.