We absolutely enjoyed our stay in Antonia's flat - it's newly renovated, super clean and very well located, just a very quick walk to Thissio and Monastiraki - so perfectly connected to both the airport and Piraeus, as well as very close to the Acropolis, etc.
Antonia and her son were amazing hosts, providing all kinds of maps, treats (even some fresh strawberries!), and advice, and Antonia even organised for us to stay with a friend of hers when we unexpectedly had to stay another night in Athens! Altogether, I can whole-heartedly recommend staying with her, you couldn't be better set up to explore Athens!!