Although Ana's apartment is not exactly in Lisbon city centre, you can take the bus or tram and you'll be there in about 15 minutes. Her place is right in front of the popular Pasteis de Belém! Restaurants are nearby and there is also a big park/garden in the area. Ana does not live in the building but you can always message her if you need anything. Because Ana doesn't live in the building I didn't interact with her much but she was very friendly when we met. I'd definitely stay at Ana's again if I return to Lisbon.