Books still matter. I am now buying my GREAT nieces and nephews books about New York's great museums. My favorite kids book about MOMA is called "Seen Art?" . And, kids under 16 are FREE at MOMA.
There are things to do with kids every day of the week and special family tours that usually happen on the weekends or during school vacations. If you get the FREE audio sets during your visit, some paintings have a kids' description as well as an adult description. The kids' description is always more interesting.
As a member, admission is free for me and $5 for adult guests. Last week I took my GREAT niece and nephew C and H for a short visit to the MOMA lab at the end of the day. In about 20 minutes, they figured out the computer art software and produced these pictures.