Right off the top of my head I'd suggest:
Walk down Main Street and turn right at the hub, then...
Space Mountain
Carousel of Progress
Buzz Lightyear's Space Ranger Spin
Tomorrowland Transit Authority
Stitch Encounter
Astro Orbiter Rockets
Adv. of Winnie the Pooh
Mad Hatter's Tea Party
Dumbo, the Flying Elephant
Snow White's Scary Adventure
Pinocchio
Mickey's Philharmagic
Peter Pan
it's a small world
Haunted Mansion
Liberty Square Steamboat
Country Bear Jamboree
Splash Mountain
Big Thunder Mtn. Railroad
Pirates of the Caribbean
Aladdin's Magic Carpets
Enchanted Tiki Room UNM
Jungle Cruise
Swiss Family Treehouse
Have a "Dole Whip",
then jog back to Mickey's Toontown Fair and see Mickey.
That ought to get them through the first couple of hours.
Then, take the Steam Train back to Main Street or Frontierland and have another "go" at it.
At 3pm or so, they can enjoy the "Sharin' a Dream Come True" Parade
and at some point see "Cinderellabration" on the Castle Steps
(but that might be a bit too much excitement).
Then stay after dark to see "SpectroMagic" Parade and "Wishes" fireworks.
That's about all there is to the MK these days.
(Except for "Character Dining" in the Castle, the Crystal Palace and Liberty Tree Tavern. The nice "strolling" shows like the Dapper Dans.
AND, the countless "little things" that make MK and all of WDW so MAGICAL.)