I don't think it is about an age, I find it's more about the LO's interests when it comes to activities.
I go with what excites them, which is the unique thing we can do over larger nurseries.
Go with what they like, introduce their next next steps through where they take their play / talking and opportunity play...

I have LO's with diverse personal interests, one who is craft/ art motivated, another smallworld, another is only interested in dressing up as a Disney princess, one who is ball motivated and, to my DH delight, one who relishes anything to do with making, construction toys, screwing and fixing....
We have to go with their flow......it makes our job really interesting.....not pin point them in to a expected year group activity....they will get enough of that when they start our narrow curriculum and testing UK school life!