We could not have been happier with our stay at rue Fondary. The owner, Emmanuel, was quick to reply to email questions about the house and the neighborhood, and his son met us at the house upon our arrival and gave us a thorough tour and explanations. They both speak English.
We were a couple staying with another couple and their 2 children, aged 3 and 7 years of age. The owner provided a high chair as well as a small crib-like bed. Best of all, there were mats and many toys to play with, including a small tent in which the kids could hide! It was ideal. The kids enjoyed feeding the fish in the very large aquarium as well.
As for the adults, we couldn't have been happier: there is a mud room upon entering, with a large closet. The living room was large and comfortable, and the dining room could comfortably seat 8 people. There is a full bathroom/shower/bath on the ground floor, with a washer/dryer. The kitchen was large and fully equipped.
On the second floor, there is a separate toilet off of the stairwell, and 2 bedrooms, one with its own shower/sink.
There is a large bedroom on the top floor, with skylights. There is also a loft-like space overlooking the living room with a small bed. It's not really suitable for sleeping, but the kids enjoyed going up there.
The house is bathed in light, and is lush with tall house plants. It's also quiet and we slept well at night.
There is a booklet with easily understood instructions in English for the wifi, feeding the fish, how the windows work, dishwasher, washer/dryer, etc... and where the grocery stores are (four within easy walking distance), and cafe/restaurant recommendations. There are two boulangeries at each end of the street with many more in the neighborhood. There are three metro stops (La Motte Picquet-Grenelle, Avenue Emile Zola, and rue du Commerce) within a 5 minute walk.. The Eiffel Tower is only a 15/20 minute walk away.
The Rue du Commerce is a lively commercial street, right around the corner from the house, and the outdoor market "Marche Grenelle" (market) by the La Motte Picquet Grenelle Metro station is a delight on Wednesday and Sunday mornings. Not to be missed.
All in all, we were extremely happy with our experience and with our interactions with Emmanuel and his son. Those who want to stay in a real neighborhood in Paris, away from the tourist areas, yet still easily accessible to them, will find much happiness here.