Unfortunately there is no definite answer AFAIK. I have been to Mauritius, Singapore, Dubai and Abu Dhabi lounges with my 1.5-3 year old kid and only in Dubai lounge I was asked about his age. They wanted to know if he was above 3 years to decide to charge or not.
Secondly, to answer your question specifically allow children as long as parents have access.
Some do ask you to swipe extra for them. This swipe itself can be 2 ways - some ask you to swipe as a guest on your existing card and some are ok with using any other card of the parents to swipe [basically you need 3 cards in this case].
One thing that always works in such cases is just being nice and polite to the lounge staff at the reception.