Margherites place is perfectly located to visit paris. Only 100m away from several metrostations. Walking distance from sacre-coeur, montmartre, ...
We didn't meet margherita, but her boyfriend Marcel met us to give the keys, and offered to help us, in any way.
The appartement is quite old, but it was very clean, and it has everything you need for your stay. It is big enough for two persons, and even tree or four persons could stay there, if you don't plan on spending all the time inside.
If you are looking for a decent and affordable 'base camp' from where to visit paris, i can highly recommend it.