France and Italy...or....

How many nights total; how many in Amsterdam and in Brugge (2+2, or 2 nights for both)?

While you are in Paris, two of your group will go to Flanders, correct? I think it's wise to split up according to your interests.

If 2+2+3, you have 8 or 9 nights left. Personally, I would spend a couple more nights in Amsterdam and Belgium and the rest of my time in France.

If you are set on the Amalfi Coast, I would fly from Paris to Napoli; you are still about 3-4 hours away from the Amalfi Coast. Let's give the Amalfi Coast/Sorrento 5 nights, the other nights in Roma and fly out from there.

Italy seems way to far from the other stops to make sense. For war sights, you could also consider Verdun and Normandy instead of, or in addition to Flanders sites. I would not drive all the way back to Flanders from Paris, was that what they were planning? Ghent is also worth a visit in Belgium--speaking from my research, have only actually been to Bruges and Brussels. Brussels has a reputation as boring but I think it's somewhat underrated, based upon a brief passing through visit.

Are you planning to use the car just for Flanders or for the whole trip? You are likely to pay huge drop-off charges if you return the car in another country. It may be worth it for 4 people, but take it into account. It may even make sense for the girls to go to Paris while the boys tootle around Flanders, then for them to take the train to join you in France. You may only need a car for a few days in France. You may find that the train fare from Belgium to France is cheaper than the drop-off charge. If you buy well in advance, Brussels to Paris is only €29. Drop-off charges can be several hundred euros.

Lots of great places in France to visit.

Normandy is a bit out of the way, but a great area to visit.

Another great area that is a bit out of the way is the Loire Valley, south of Paris.

Probably better in route from Belgium and Paris would be Strassbourg and the Alsace region of France (close to Germany and Switzerland) then proceeding down south to Burgundy and Provence (down the Rhone River). Lots of great places, wine country of Burgundy, Many ancient cities in Provence, including Arles, Avignon and more. Then the Riveria, with Nice, Monaco and a great little city called St, Paul de Venice.

Thank you everyone.
What if we actually change this up and do Italy first? Then go from one of the closest places in Italy to Paris? Do 2-3 days there, then get on a train and go to Amsterdam, Brugge and Ghent (thanks for reminding me!) And fly back home from Amsterdam?

Visiting Italy first can work. Only 8 days,
Venice 3 Nights, you will need an extra day to recover from the jet lag.
Florence 2 N
Rome 3 N
Fly to Paris, 3 N Let your husband and son venture off to Normandy or Flanders, meet them in Brugge.

Brugge 2 N
Amsterdam, 3 N

Flying to Paris is cheaper and quicker than the 12 hour train.

This is fast paced. I would cut out Florence and then Amsterdam so you and your mother can slow down and enjoy yourselves.

Dear csu15269,
Thank you very much!