Gwenaelle was a wonderful host! She was flexible with arrival and departure times, and even had one of her sons help me carry my giant suitcase up the 7 flights of stairs!
The room is very small (I don't think it would work for two people), but has absolutely everything you need--shower, toilet, hot plate, fridge, twin bed (that doubles as a couch), closet where you can hang clothes, even a desk for working and/or eating. It's quiet, clean, and comfortable. The apartment is also excellently-located; the metro lines 6 and 4 are literally outside your front door, there's a supermarket nearby, etc. You can also easily walk to the Luxembourg Gardens and to lots of restaurants in the Montparnasse area.