I can only recommend Maria’s place. The city is easily accessible but the area is peaceful, with several restaurants nearby. The place was clean and actually a lot better in real life as in the photos, perfect for a couple or 2 friends. Best deal in Lisbon where I’ve ever been, really.
I would recommend the travellers to bring earplugs if you are a troubled sleeper, because you may hear the neighbours sometimes - but we were never bothered by this.
Maria was an extremely kind host and we could not have wished for a better stay.