Diamond Princess:
https://en.wikipedia.org/wiki/2020_coronavirus_outbreak_on_cruise_ships
I am still looking for age data.
Ages and all sorts of Diamond Princess data here:
https://www.niid.go.jp/niid/en/2019-ncov-e/9417-covid-dp-fe-02.html
I could not find the Diamond Princess positive test age data, but I did find this article about children spreading the virus to others:
https://www.statnews.com/2020/02/27/coronavirus-kids-what-role-transmission/