We had a great stay at Mafalda's apartment. The apartment is located in an old monastery at the edge of Alfama. It is about half an hour walk from Praca do Comercio and about 10-15 mins walk from the centre of Alfama with its many bars and restaurant. The area is very calm and quiet. The apartment is also very quiet and has shutters in the bedroom which don't let any light in so it's great for someone with light sleep who needs silence and darkness to sleep well.
The apartment has everything you need, even a washing machine. Communication with Mafalda was very good, she was very responsive and gave us directions on how to get to the apartment from the airport (a short Uber drive). She also left a bottle of wine and chocolate Easter eggs for us as we stayed there during the Easter period.
Overall, it's a very nice place and I'd recommend it to anyone, especially someone looking for a calm and quiet place a bit off the city centre.