What age do you want kids ?

I am quite a young mum, and feel like everyone else with babies are in their early to mid 30s. All of my friends are saying they won’t even think about kids until their thirties.

Is this an Australia wide thing ? Just cost of living related or something more cultural ?

Because while it’s potentially easier financially to have kids when you are older, it is a lot harder physically (for the mother, but for dad too I guess with lack of sleep). Do people realise this ?

What age do you want kids ?