I stayed at Noemi's in January for a week as I visited the Roma Tre University. Her house was short walk to the University and is a few(maybe 7) metro stops from the city centre. Her house is around 5 minutes walk from the metro stop Basilica San Paolo. It is also 4 metro stops away from the Colosseum(less than 15 minutes).
Noemi was great, and so is her house. The most outstanding part for me was that her house is exactly as it looks in photos. No filters, no photoshop. It is as delightful as it appears. The house was always clean, and being January, it was always warm as well.
Noemi herself was warm, informative and always kept in touch. In fact, I was robbed on the metro and she was awesome enough to lend me some money in the meantime. (Tip: watch your bags on the metro, especially when getting off and on). She also gives you space and is not intrusive after you've had along day. She has maps and guides for the city too. My best part of the stay: Breakfasts. Noemi bakes amazing treats!
There are restaurants a walkable distance to her house, and a McDonalds too. Being a University district, the meals aren't too pricey.
I would definitely stay with her over and over .