We had a great stay at Ana's place in Lisbon.
We were collected by Silvia at the airport which made getting to the apartment and getting acclimated to the city was particularly easy. The space is very nice and actually a little larger than I expected given it is a studio. Ana and Silvia also made sure they were available during our stay if we had any questions or concerns (which we didn't).
The neighborhood at Ana's place can look a little rough when you first arrive; however we didn't have any problems and felt comfortable during our stay. One thing I would mention is that Silvia provides an option to pick you up at the airport for 25 euro, but you're probably better off taking an Uber which will only be about 8-10 euro. Having said that, she tells you a little about the town and makes you feel welcome, so there is a benefit to using her service instead.
Overall I think Ana's place is a great option in Lisbon and we would have no problem staying again, particularly for the price!