We stayed at Maria's place a little bit more than a week, and it was perfect from start to end. Maria and her daughter welcomed us and explained the house rules. The neighborhood is very good, although a bit far from some public transportation - like the tram - but we loved the walk down the hill, with a pretty awesome view of Rome. The room is big and very confortable, with a private balcony and the bathroom very close. We loved the room and would definetely recommend it to anyone wanting to stay with a true Italian family.
We even got to meet Maria's granddaughter Petra, whose kindness potisively impacted us, and who was very pleasant to chat with.
P.S.: If you're lucky like us you'll try Maria's Limoncello, which is the best one I've ever had.