What is considered the best time to have kids?

Tesia
My mom has been having kids since she was 16 and she just turned 40 and her youngest is a year old. So I've gotten a pretty good idea of the spectrum of energy levels needed to raise a child but what age is actually the best? I want to have kids now but I'm not really ready. I know I don't want to have kids after 35. (Just for health and safety reasons) what do you think?