I highly recommend to stay at Marie's!
The location of the apartment is just wonderful. Le Marais is for sure the most pleasant area to stay in Paris. It is very central but at the same time it still is safe. I am a girl travelling alone and I never felt uncomfortable walking around there.
The apartment itself is really cute,calm,clean and perfect to stay in for one person.
Marie is the loveliest host you could ever wish for. She was always kind,even after a long day of work she is open for some chats. She can give you helpful tips where to go or what to do. I even learned some French expressions!
Sooo...the five days I spent there were fantastic, I will for sure come back and would definitely book Marie's flat again.