There is Milo cricket for the little ones, aged 5 - 8.
The MILO in2CRICKET program is designed for boys and girls from 5 to 8 years old. It is a fast, fun and active program that emphasises maximum participation, basic motor and cricket skill development. It is experience based and builds its foundations on the essentials for lifelong involvement in physical activity and sport.
Kids get a backpack and some other cricket goodies
From 7 upwards they can take part in the T20 blast.
MILO T20 Blast is a super fun, social, safe, cricket program for boys and girls. The program is much shorter than traditional cricket, with a maximum of 90 minutes playing time. All the equipment is supplied and the games take place at the same venue each week, at a local cricket club or community centre.
More info can be found here