Lia is a gracious host. She was very prompt with communication and very accommodating. When it became clear during the first night that the arrangement would not be adequate for us to continue there (see below) and we cancelled our remaining nights, she graciously returned her second night's charges even though we cancelled a few hours too late to be reimbursed automatically by airBnB according to the refund policy on Lia's page.
The reason for our cancellation during the first night was the level of noise. The description does include the phrase "with airplanes reminding us that we live in a European capital," but that does not quite do justice to the fact that the building is directly in the path of the final approach to the airport for one of the two runways at the Lisbon Airport. After midnight, the air traffic slows, but we heard at least one descent as late as 2:00 AM, and the traffic resumed at 6:00 AM. Since the airport is only 3.0 km away as the crow flies, a typical airplane approach angle of 3.0 degrees means that approaching airplanes pass about 300 meters directly above the building. I have lived in urban centers in Spain and am used to noise such as garbage trucks coming by at 1:00 or 2:00 in the morning. However, the noise here was a different level, especially with the windows open. I am generally a rock-solid sleeper, but I was only able to sleep for about four hours, while my mother did not sleep at all. This problem could be mitigated somewhat by closing the windows, but in the summer, the room then gets too warm for sleeping (afterwards, on looking at the photos, I saw that the photos show an electric fan in the bedroom, but we did not see a fan when we looked around for one).
My strong recommendation for those who plan to stay here is to bring earplugs.