It's small but there's plenty of room for one, maybe two if you just need a place to stay. The bed isn't for everyone but it's exactly as it looks - if you're okay with that, then Marie's place is a charming base to explore Paris from. It's close to the metro and bus lines and easy walking distance to some lovely areas.
In addition, Marie is a very thoughtful host, leaving lots of little things to make your stay nicer. Definitely recommend!