I grew up in SF and still have family living there. The Washington Pavilion was my high school. I was teh last class to graduate from that building, it was very sad when they started the renovations.
We used to go to Gigglebees with my younger siblings and I've taken my kids there a few times. It's an arcade which isn't a big thing but the robotic waiters are fun.
My uncle works at the Butterfly House. He took my kids when they were visiting for an extended vacation with my mom and dad. They loved it.
I know they've done a lot with the zoo, I haven't been since I left home.
I'll have to call and check if it's still there; but I enjoyed the old-fashioned soda fountian at Zandbros.
While you're in town, check out Carnaval Brazilian Grill. It's north of 49th and Louise. My DSis and BIL took me there and it was so yummy. It can be pricey; lunch is affordable though.
I'll have to ask my DSis what else you can do. She might know of a few things during March or if there are other things for families during the time you're going to be there.