Separately: a harbor seal has been hanging out at Pier 39's sea lion docks since Friday, which is genuinely unusual — seals and sea lions don't typically share space without tension, and this one's apparently holding its own. No ticket required to watch from the observation deck. It's a free, dumb, excellent piece of wildlife programming.
If you're building a full day around Golden Gate Park with kids in the almost-teen range, the JFK Drive bike loop threads past the Lindy dancers, the disco skaters, and usually live music near the Whale Tail sculpture — all free, all mid-morning on weekends. The Big Art Loop route (bigartloop.org/map) maps a longer version that hits public art across the western neighborhoods and is legible enough for kids to navigate themselves, which keeps the energy up.
If you have two hours: Hit the Tea Garden at 9am (free), walk to the Whale Tail area to catch the skaters spin up around 10:30, then bus to the Embarcadero and walk Pier 39 to check on the seal. You're done by noon and you've covered three things that don't overlap with anything you did last weekend.