What are fun developmental milestones for almost-1st graders?

I know this is a really specific question, so it might not get many answers.

I’m a nanny of two 5 year olds who are finishing up kindergarten. Academically and socially, they’re marvelous. I’m starting to think there are some things they should know how to do, and since I have them full time this summer I want to set some goals. I’m not 100% sure what’s appropriate though. How old were your children (or you, if you remember) when you were able to ride a 2 wheeler, tie your shoes, shower alone as opposed to a supervised bath, or blow bubbles with bubble gum? (And anything else I might be missing, too.)