Our experience was quite a disappointing one and we met other travelers staying in the apartment who were also unsatisfied with their stay.
The many little flaws of the room and facilities (apartment door that would not close all the way - very unsafe, uncomfortable pillows, broken elevator, parts of the apartment that were still under construction…) plus the little episode of us being downgraded last minute to a smaller room with less facilities together led to a stay that was less than ideal. In addition, the location of the apartment was not optimal, for the same price I believe one could get a place more centrally located. Julia seemed to be a nice lady, but we unfortunately would not recommend her apartment for your stay in Lisbon unless there were no other options more convient.