Thanks for the reply @jasonlutes, I’m glad my notes were of some use!
We also used a second page of paper to write down notes about the map or fiction that we established. Probably not unusual for sessions like this either in the form of GM notes or index cards.
My favorite chain of collaboration was when my 8 year-old liked my name Crystal Pool, added the Ruby River and said the water was reddish. We didn’t have a reason why, but later he mentioned off-hand that there’s a lot of iron nearby. I said hey maybe the river looks red because of all the iron in the soil. Later we rolled anachronistic mounts and (after I explained what an anachronism was) he said ok they have motorcycles-no-wait-bicycles, so we decided they are made from the local iron and he added they have a special button to boost and go fast. It’s called Rainbow Junction because the mist hanging in the jungle creates near-constant rainbows. The default move in the 8 year-old playbook is definitely Spout Lore!
Also he rolled “notable gait and voice” for his carpenter and demonstrated a goofy walk and voice that had us both cracking up. These were such fun and memorable moments. Thanks!