Hmmm this is interesting. I am keen to know to.
I think by 6 years old, parents will need to start training the kid to shower on their own. So that when the child goes to student care centre in primary one, he is independent. I heard the staff at the day care centers will not help to shower the children.
But if the child confirm not going student care, perhaps there no hurry. But usually chldren's self awareness will strengthened as they grow, by primary school, they may not even want parents to help them to shower.