when I was 4 or 5, I helped my mum with lots of things for my little brothers ... changing their nappies and their clothes, playing with them, bathing them (together in the bath, generally with some supervision) and heating up bottles etc. Fetching things for mum, packing away toys, rocking them or gently swaying them in the bouncer, whatever.

there were lots of things which I can remember doing to help

my DS will be 21 months when Ziggy arrives, so I'm guessing he won't be doing any of those things though