Cathay Pacific, Qantas lounge access for families

They do count children as a guest for QF Plat. I am a QF Plat, when I was in HK last year flying back on CX, I took my wife and my daughter (2yrs old) to the Pier-First, the attendant said I can only take 1 guest as child of any age also count as a guest. The lady was in a good mood so still let us in. But strictly speaking, child counts as a guest.