Many people choose to stay near Termini but I think staying near the Vatican is a good option as the Vatican Museum tour can be quite taxing. You don't have to get up that early if you are NEAR the Vatican and the view at night is also beautiful. This place is well-connected to the other main attrations of Rome through the metro, bus, and tram.
That said, Carla was most accommodating and helpful, with restaurant and gelateria recommendations and getting about in town. She was very clear about the house rules (which is very reassuring) and check-in process was also very convenient. She was accessible throughout our stay and attentive to our needs.
The kitchen is well-equipped so you can do some grocery shopping nearby and cook something up or you can eat out.
One downside is the garbage trucks on the street making some noise in the wee hours of the morning, but that was a minor problem. I was the only one in the family who noticed it at all.
Carla's home provided a true sanctuary to our family in the sweltering heat. When I asked my youngest boy what his favorite place in Rome was, he said, HOME!