I stayed in Elise's apartment for 4 days. It was a wonderful experience! We were 4 friends so it was not a problem to share the room- there is space for everyone and if someone wants his intimacy, there's a curtain that separate the loft. We communicated with emails before our arrival- elise is a timely person! She answers in a few hours and she is very kind and available.
The apartment is 5 minutes walking from Sacre Coeur and 5 minutes from the metro Chateau Rouge. Moreover, there is a Carrefour 2 minutes walking and also others metro's station. It is located in a multicultural zone, so you can both enjoy Montmartre and the french culture and have a delicious african dinner :)
I would recommend Elise's apartment without doubt.