The age restrictions seem to vary according to the time of day and event. For example, I took my 10 year old to an evening art opening mid-week and there were several other kids there too, but that tends to be an exception in the evening at least. During the day, such as lunchtime, there seem to be no age restrictions. They tend to come in to play in the evening. If you're in Gabs I'd phone them and ask as things have changed quite often with it being fairly new. Unfortunately, their website isn't working at the moment, but you could phone 192 and get the number.
Get quick answers from Sky Lounge staff and past visitors.