In 2022 we made 2 week-long trips to Paris: one in April with our daughter’s family including a 10-year-old girl and 6-year-old boy and their parents (6 total) and another trip in September with our neighbors (the 4 of us are retired).
The trips were both fun and enjoyable, but different! We did things in April that we didn’t do in September. In April we did not stay or go to museums for a lengthy time, and we went to places I didn’t know existed and to restaurants that had kid friendly meals. All our travel was Metro, Bus, and walking.
In September we went to museums we had not visited on previous Paris trips and to the gotta see ones for our never been to Paris friends, ate at restaurants that were not pizza and hamburger oriented, leisured at sidewalk cafes, and went to excursions outside Paris.
Here are some of the places that were great with the kids:
Jardin de Plantes - Great park with natural history and Evolution museum & nearby Zoo - Galleries, Gardens, Zoo - Jardin des Plantes (jardindesplantesdeparis.fr) and Lunch at the nearby Monster Diner https://mobsterdiner.com/
Choco-Story – chocolate museum and make your own chocolate Choco-Story - Paris - Choco-Story PARIS (museeduchocolat.fr)
Jardin de Luxembourg – Wonderful park for kid and adults love to enjoy people watching and have fun with the sailboats Jardin du Luxembourg - Paris tourist office (parisinfo.com)
Lunch at Pink Flamingo PINK FLAMINGO, Paris - Le Marais - Menu, Prices & Restaurant Reviews - Order Online Food Delivery - Tripadvisor
Private cruise on the Seine – with a group it is fun to arrange your private cruise down the seine going past the Tour Eiffel - Green River Cruises - Pont Marie - Les Maquereaux - Green River Cruises - Your private cruise in Paris (greenriver-paris.fr)
Pere Lachaise Cemetery
Disney Paris. The kids loved this and, with careful planning, both parks and important rides can be done (paying extra for front of the line passes).
And of course, McDonalds and Starbucks!