Maria's place is right in the heart of Sintra village - literally a few minutes walk from the shops, restaurants and other tourism infrastructure. I was in town for a wedding and they kindly allowed me to check in earlier so that I could shower and change before the event.
The place is a converted old storage room right in the centre of the village, it has a feel of a traditional wine cellar, so very cool to keep out the high heat. There were extra blankets on hand to keep you warm if needed at night although in November this didn't prove necessary. There's a kitchen that's fairly well stocked, but no iron that I could find (not a major issue). Check out times are a little flexible, and the cleaning ladies offered to store my bags until I was ready to take the journey back into town. They even recommended a place for lunch, that was super tasty.
Sintra itself has a lot to offer, the one-way system is a little hard to navigate for getting taxis around, but it's very very charming. As I didn't have time to visit the sites, I shall probably return on another trip.