The visitors should absolutely see “their Paris” if they want to — but you do not need to turn four children into museum prisoners. Pick one icon, one experience and one good evening moment.
The palace is of course extraordinary, but with four kids I would make the huge park the backbone: Grand Canal, bikes, rowboat, picnic/ice cream, then Trianon and Marie-Antoinette’s hamlet if everyone still has energy. Add the Hall of Mirrors only if the Canadians genuinely want the classic interior.
Not a route — just components that can be combined according to heat and enthusiasm.
Choose a small number: Eiffel Tower viewed from the Seine/Trocadéro area, Louvre courtyard + Tuileries, Île de la Cité, or Montmartre. One or two are enough. A Seine cruise near sunset gives a lot of “Paris” without eight tired kilometres on foot.
An immersive adaptation of Saint-Exupéry’s story, open to all ages and about 50 minutes. It starts from €12.50 and has a children’s interactive area — excellent as the anchor of a hot Paris visit.
For something your Canadian friends probably do not expect: free summer swimming in the city. La Villette is easiest; a Seine site such as Bras Marie is more memorable when officially open.
A genuinely current, non-generic Paris experience. The European championships’ 50 m swimming programme runs this week. If tickets line up, this is a fun “we happened to be here for it” story rather than another monument.
This would otherwise be almost perfect for your group — historic fairground arts and interactive atmosphere — but visits are reservation-only and the next advertised themed public visit I found is 26 August.
Disney’s own site currently warns that its parks are full on many dates and requires dated tickets/advance registration rather than relying on the gate. Add August holiday demand and the current Chessy heat forecast and it becomes an expensive endurance exercise.
Go if the children actively say “Disney is what we want.” Otherwise, your local castle/forest/water + selective Paris options are more distinctive and much easier to adapt.