We had a fabulous time in Paris and being able to come back to Nathalie's flat at the end of the day added to the pleasure and success of the trip.
The flat is in a great location; 15-20 minutes walk (child speed!) from the Gare du Nord where the Eurostar arrives, 10-15 mins from the Gare de l'Est where buses to sights across the city leave from, 5 mins from a number of tube stations and with an ATM just around the corner.
The street the flat is on is a buzzing local hub with food shops, cafes and restaurants all along it where you can meet all your food needs. People are friendly and helpful on the whole (and tolerant of my appalling French!) and it feels safe. It isn't touristy or chic and is very multicultural, so you get a real sense of Paris life for normal people, which us country bumpkins loved.
The flat itself was absolutely perfect for us as a family of 5 (children ages 6, 9 and 11) and so nice to come back to after a tiring day seeing the sights. It was clean and tidy with a colourful, uplifting vibe. The arrangement of rooms meant we could have some adult downtime in the evening without disturbing the children. It was surprisingly quiet at night due to the flat being on a private yard (I had expected all-night noise from traffic/revelers/sirens) and there was even black-out of sorts on the curtains in the bedroom which I always appreciate. It was easy to find what you needed for cooking and there were loads of towels offered.
The flat is Nathalie's home and there is an expectation that you respect it as such, but she had done her best to make it easy to work around her personal belongings, and even with three fiddling children it worked fine. Actually it was really nice to stay somewhere with the personal touch and a bit of soul.
Nathalie herself was friendly and helpful and easy to communicate with, and check-in and out was easy and she offered that we leave our luggage at the flat after check-out on the day we left if we needed to. I couldn't recommend her place highly enough; staying in such a Parisienne setting added so much to our experience and we'd love to stay again one day.