CA bound!

The kids, me & my mom are off to sunny CA (not til Aug, but still...) As soon as baseball is over and Speck gets his tonsils out we are headed to San Francisco. My brother is a buyer for Piperlime and moved out there about a year ago. We haven't seen him since he left. I am so excited! Trying to decide what is a "must" see. He lives within walking distance of Alcatraz so I am sure that will be on the list. With 3 kids and public transportation it will be interesting. He says the city isn't really "kid friendly". There are a lot of tourists but not many families that live there. At least we will have 1 adult per child! If anyone has any suggestions where to go (or avoid) please share.