Coyote Point is a really nice place to visit when you want to see animals (they have a small "zoo"), want to be inside, or otherwise need to entertain your kids. It is really convenient to 101 and downtown San Mateo. They have summer, spring, and winter camps for kids, and "Toddler Tuesday" where there is some craft project for toddlers.
Unfortunately, there is talk of closing this museum down. I wouldn't be surprised if the local yacht club and golf course wants to take over the gorgeous land it rests on. This would be a big disservice to the kids (and adults) of San Mateo and surrounding communities.