If you're in Ontario, then babydom is right: 5 kids at any one time per premises, not per adult. Your own child will only count as one of the 5 until they are 6, under Bill 10.

Being over in numbers, even only occasionally, even just for 5 minutes, is technically illegal and under the new rules, you could be fined up to $250,000.

If you can manage to juggle days, you could have as many kids as you wanted enrolled, as long as you never exceeded 5 at any one time, including any of your own under 6.