If you have time while at Sleeping Bear you might stop in at night to the Cherry Bowl Drive-in. An old fashioned drive in theater with kid friendly movies.
Do the dune climb and Stocking Driving Tour just south of the climb.
If you have a dog there are several 'dog friendly' beaches along the way.
North along the west end of the peninsula is 'Fish Town'. Looks alot like the Popeye movie but great little place to visit. There is also several old towns just north of the Dune Climb.
Most of all, enjoy.