The Moffat Museum — Eleanor Estes

There has never been a museum in Cranbury...until now.
Among its treasures are the first bike each of the Moffat kids rode, stardust from a meteor that fell to earth, a beautiful painting made by Sylvie, and-most spectacularly-Rufus, the Waxworks Boy, who is as funny as he is waxy. The museum is so interesting that Mr. Pennypepper even brings tourists to visit.
But the museum is really for Jane, Joey, and Rufus themselves, so they can remember all the good times they've had. Because life is changing for the Moffats.
Yet even if Sylvie gets married, or Joey goes off to work, or Rufus grows up, one thing will never change: The Moffats are still the sort to hilariously fill even the most ordinary day with extraordinary fun.