The US Fish & Wildlife Service has a feather atlas to help people ID North American birds.
It’s not perfect as they may only have feathers from one or two individuals, and like people birds of the same species aren’t all identical. But it’s still a good resource. Plus it has an Identify My Feather feature that’s fun and interesting to use.
May I suggest sock tag - use a rolled up sock (or something similarly soft). Kid runs around while you try to tag them with the sock. Similar to dodgeball, but no one should get hurt and you get to sit or lay down while they burn off energy.
Brought to you by a parent with chronic pain