Marion's place was great. My husband and I stayed there with our four month old son. It was great to have the kitchen and living room space for eating in a few meals and so that our son could spread out in between excursions. The apartment is perfectly located in the Marais and is super convenient to many sights. We walked everywhere and also took the subway which is closely (hotel de ville stop).
Check in was also easy. We met Marion's friend Pascal at an agreed young time outside the building.
Highly recommend!