If you're looking for some free fun, you can get tickets to the International Gem and Jewelry Show for free on Goldstar.
You need to plan in advance, because these may go quickly (or not). But it doesn't hurt to get the tickets now in case you want to go. You can see more about the show here. Note that kids 8 and under are not permitted.
Friday, May 30 from noon to 6
Saturday, May 31 from 10 to 6
Sunday, June 1 from 11 to 5
Where: San Mateo
Who: Children 9+ and adults can attend
Cost: free with this link, but there's a $3.50 service fee. Tickets are normally $8 plus the fee.
While you're there, check out the other offerings by Goldstar, which offers event tickets at a discount. Frisco Kids is an affiliate of Goldstar, but we're very into discount event tickets.