Me and two of my friends stayed in Cristinas apartment for one week.
We had a good stay, the place is stylish and clean and located in my absolute favorite place in Lisbon, great for less touristy feel with good restaurant and walking distance to everything including nice parks.
I would recommend that apartment for a couple sharing the big bed. My reasons for this is the bathroom being slightly not so privat, and the small bedrooms bed is not that comfy. My friends who shared the double bed said there bed was very comfy tho.
We managed to lock our selfs out of the apartment one day, Christina was very understanding and helpful to get the situation sorted out. She was also very fast to reply if we had any questions.
I would recommend checking the house rules before you book as they are slightly unusual or should I say more strict then what I am used to, but thats fare enough its a nice apartment and I understand she wants to look after it. If you want recommendations from your host Cristina has you covered with instagram accounts and write ups in the apartment with local recommendations for what you will be looking for. The check in and communication was very good. Thank you for a nice stay Cristina :)