If you don’t accompany your children, you will be in breach of the by law.
Defining “accompany” would be a field day for lawyers.
As an aside, modern strata buildings don’t cater for children’s play activities. In my area I see an increasing number of families using the local park for their kids’ activities.
That’s what they’re there for. But some family friendly blocks do have a play area, often shared by a number of buildings. They should be a condition of planning approval (but they’re not).