Thanks to a homeschooling friend, I found out about a local-level geography bee put on by homeschoolers, and dd9 participated in it this week. She did a prep class with some other homeschoolers for an hour or so the week before and then some map reviewing at home. That's basically all we did to "study" for the bee. It was by no means a high-pressure event for her.
She ended up enjoying the geography bee and doing relatively well (4th place). I like that she could be in a real contest where she got to experience a bit of the adrenalin of competition and make some successful educated guesses. I also like that it reinforced to her how much she has been soaking in during our home studies of world history, literature, and science.
I wonder if there are other academic competitions I should look into for the future. I only did school spelling bees as a child. (I still remember getting out on "cataclasm" in sixth grade because my copy of the spelling words list made it look like "cataciasm" due to a defective "l". Stupid copy machine.)