Boat ride along the Bund, either daytime or evening for the lights?

There's a museum of Chinese history on the Pudong side that had a lot of scenes with manikins talking (I'm not sure how to describe it) in fake reconstructed rooms that could appeal to kids (and be educational) in small doses.

Exploring the Shanghai Expo grounds could be fun.

Don't forget the Maglev.

There are groups performing in main street between People's Square and the river in the early morning and then along the river, including group dance and kites.

Limited exposure to some of the historical communist party sites, including "XXX lived here many years ago" could be interesting and educational, depending on whether their schools have started to teach them about the history of China and communism.