Sophie was a great host! I was really surprised about her box of maps and tour guides for Paris. It was MAGICAL. I had no idea where she got maps of so many languages from. I arrived late (11PM), and Sophie was nice enough to wait for me and show me the house. We had great talks and enjoyed half of a soccer game together (because I arrived home late).
The house is pretty central. 30-40 minutes away from the Louvre by walk. It was a down-hill walk, so I definitely enjoyed my first morning. If you take metro, I would say that everything is within 30 minutes, and Sophie's home is literally 5 minutes away from the metro station by walk.
Would highly recommend staying with Sophie for Paris!