We had a wonderful experience at Hélène's studio and were met with open arms by her mother who extended her hospitality without reservations. We went to dinner with her and her brother who happened to have studied at my Alma Matter at the same time I was there, studying the same subject I was. Small world, wonderful family whom we hope to stay in touch with.
The apartment was great, just as we expected: a rooftop pad with beautiful views right in the center of Paris. It felt safe, convenient, and seeing Notre Dame at 6am while getting breakfast for the family at the local bakery was.... Amazing.
Our sons (5 yo and 8yo) still speak of the apartment and "bunk bed" (the master bed is up a staircase right under the roof), and want to "live" in Paris again.
My only recommendation, is that if you have mobility problems, sleeping on the sofa bed might be a better option than going up to the master bed (I've taken some amazing Paris rooftop pictures from that master bed)
There was a small elevator to get to the studio (about 2 feet deep by 5 feet wide), but we all fit in it without suitcases.