My family and I just wrapped up a weeklong stay at Jean-Marie's apartment in Paris and we had a delightful time! We have three children--ages 9months to 7 years old--and also brought along my college-age cousin, so we were very thankful for the many bedrooms. The flat is beautiful and spans the full floor of their building so there are windows for fresh air and views from every side. My kids loved the people-watching of the bustling neighborhood down below. The flat is decorated with a lovely mix of furnishings and several lovely antique items. In addition, there are books and toys to entertain the children. The kitchen is compact, but very well stocked with all that you need to prepare meals--we did breakfast each day and several other meals at home.
You could not ask for a more ideal, central location in Paris! The neighborhood was bustling and lively, and the Odeon theater is just a half block away with a charming array of tables set out in the plaza to sit and enjoy a drink in the evening. The Luxembourg Gardens are two blocks away and the nearest entrance to the flat happens to be the most scenic, entering right by the senate building with beautifully manicured gardens and the main plaza & fountain just beyond. Our kids were delighted by the small sailboats you can rent there (a few € for 30 minutes) and begged to go back a second time later in the week. There are also several play areas for the children to enjoy with climbing structures, merry-go-round, and zip lines. We spent an entire morning here strolling around and enjoyed lunch at one of the charming cafes in the park. I would consider it a "must-do" for any family visiting Paris!
The apartment is also walking distance to the Seine, Louvre, Notre Dame, St. Chapelle, Musee d'Orsay, incredible shopping (both large stores along St Germain and smaller boutiques along the side streets), and many other sites. The immediate neighborhood is chock full of book stores--you could easily spend an entire day (or more) just browsing and exploring all of the treasures.
Jean-Marie and his family were very welcoming and helpful. He provided us with many recommendations for the best spots in the neighborhood, from grocery stores and bakeries, to restaurants and attractions. He gave us a tour of the apartment upon arrival and provided instructions on how to work everything. Given the historic nature of the building, there were a few quirks (traditional herringbone floors that creak a bit, no air conditioning) that took some getting used to, but we found it charming. Jean-Marie provided contact information and was easily reachable, if needed, but we had no issues during our stay. Very responsive and clear communication.

I would highly recommend Jean-Marie's apartment to anyone interested in experiencing Paris like a local. It was a delightful week and we hope to return!