The appartment is very cozy and nice and clean. We especially liked sitting in the Patio. Barrio Alto and some of the main attractions of Lisbon like the Tram 28 and the Time Out Market are in walking distance and Sissi and her children gave us good tips on what to do.
They were very caring and nice and we had a very pleasant stay in their appartement and in Lisbon :).
I would definitely come back.