Mathilde is such a wonderful host! I stayed at her place for 8 nights. She is the incarnation of Airbnb spirit, which is cultural exchange between the host and the guest, giving you local tips. She was very sweet and very thoughtful, also very arranging. We had great conversation every night over dinner and every morning before the day starts. I would definitely recommend staying with her, especially for a longish stay.
Her place is nice, quiet and peaceful, at the top of a steep hill but there is a lovely road, less steep that makes you see the view all the way to the ocean, in a very peaceful and green residential area. I will definitely come back to her place if I ever go back to Sintra, not just for the place but surely for the wonderful exchange with her. :)