I think you will be all right. Luxair will print all your boarding passes at LUX airport, including the QR ones, and check your luggage through

There is quite a bit of walking at CDG and it takes a while, yet it is all quite pleasant. It’s a five or ten minute walk from the Luxair aircraft at CDG Terminal 5G to where the transfer bus goes; then, every few minutes, a bus leaves for the main terminals. It’s a nice ride with good views. Then, a second transfer bus, as you say; although I walked - it took about 12 minutes.

There’s priority security at CDG for QR J passengers and, if you have time, a lovely lounge there. Terminal 1 has been refurbished and is very pleasant overall.

it took me just under an hour from LG aircraft to QR lounge. I enjoyed the journey and had a great time. I’m sure you and your 8-year-old will too

Obviously, if there’s a delay to your incoming aircraft, then go the check-in desk at T1 and QR will have to sort out our for you. I imagine they’ll look after you in the lovely QR lounge until a later flight.

Have a great trip!

JSB