Nervous about having enough time for customs at CDG before connecting flight.

Separate tickets or single ticket??? It could be tight as you will have to go through immigration and that is a big variable as to time. If on separate tickets, then you will walk through customs quickly but that will put you outside of security so you need to go through security again prior to you next gate. However, if single ticket and you miss the second flight, Air France will have to book you on the next available flight. May be a big inconvenienced but you have little choice.

Single ticket.

Air France is responsible for getting you to Naples if you miss your flight. You will go through customs in Naples. Immigration in France.

Are you connecting these flights yourself or did you buy a ticket to Naples from your starting point from Air France? That makes a difference. If you put the two flights together, you will not make it. If Air France sold you this connection, you might not make it because you have to go through passport control at CDG (note: I am assuming you are arriving from outside the Schengen Zone). Air France will put you on it’s next available flight to Naples. AF believes there is enough time and there will be if passport control is not backed up. I wouldn’t be nervous unless it is imperative that I catch the 9:20 to Naples or if it is the last flight of the day or if “we” is more than 2 people. Flights are so booked up these days that find seats for 3 or more people on one flight can be real challenge.
BTW, customs in Italy is just walking out through a nothing to declare door (assuming you have nothing to declare).

Thanks for the helpful replies.
Air France will get us to Naples since the entire flight sequence from Houston to Paris to Naples was booked together, so I guess I shouldn't worry too much about that. Good information that we (4 of us) will go through immigration in France and customs in Naples. We will do our best to hoof it over to immigration as fast as possible! Myself and my two daughters have dual citizenship (US and UK), so I wonder if using our UK passports would go faster? That would leave my poor husband to cope on his own though LOL!

There will be two lines for EU and non-EU passports and the EU passport line is generally shorter.

I ended up on a tight connection going to Athens via Air France. I was amazed when a man in a van met me at the base of the jet stairs and drove me over to the other terminal. He then personally escorted us through passport control to our next gate.

He looked like Inspector Clouseau, but in a gendarme type uniform. It was all rather surreal. I have never seen anything like it since then.

I would not be overly concerned about immigration, but if you have to change terminals one hour would be a really short time as you would have to pass a security check as well; and the way CDG is designed, connections are often from a different terminal.

I remember having a one hour connection Rome-CDG-Santiago (Chile) with a walk to the opposing terminal, and it was really rushed. We were a group of 100 persons, so it is highly likely they would have held the departing airplane if we were late, but I would not try it on my own. If this is your case, be sure to study the airport layout in advance and you know where you should be going.

Nothing to be nervous about you will be put on the next flight to Naples

If you were to miss this connection, Air France would be responsible to get you on the next flight to Naples that has available seating. Since you are a group of 4, this might mean you won't all be on the same flight if things turn sour. I would at least want to have some idea of where you would want to meet back up in Naples in case your group gets split (but, hey, I'm an over-planner!)

Not sure if this helps, but about a year ago my wife and I missed a connection on Air France (Vancouver > Paris > Venice) due to delays in Vancouver. Snow of all things. AF automatically put us on the next flight, which was 2 hours later. All we needed to do was to get new boarding passes. So you'll get there.