Janice and her husband were very kind, extremely responsive and helpful. The location is convenient, close to transporation and the Fine Arts Museum.
However, I experienced several issues: the light bulb of the reading lamp was not functionning; the shower handle was broken (even though I could finally manage to take showers, the water was either boiling hot or cold; I could not really have it the right temperature); and the heating was a problem: I was not really free to heat the room at my convenience because the host's parents (elderly people) live next door and the heating system is common. The heating system aslo makes a very strong noise, quite disagreeable. I had to sleep with ear plugs, and would wear them also to read or work if I needed to concentrate.
Besides that, this studio is smaller than I thought. I was alone with one big luggage and another bag; it was tight. There's no room to store clothes. And when one leaves luggage open on the floor, there's no space anymore. For a couple, it'd be extremely tight.
Despite all this, I recommend the place for whoever looks for a small room well located in Boston.