At suncorp they have locked in 30,000+ spectators today alone. It will sell out, and for the first time break the 50K for an NRL fixture there. Its like state of origin almost. Its just a pity its a final (well not really but ok) and it won't count toward regular season attendance.
Sellout by tommorow i would think, and if not, limited seats available for remaining days of the week.
**Anyway, take a look at the site ticketec.com.au, and in the section where you actually select the tickets you want it says in the CHILDREN tickets: children under 4 free on knee.
It could be possible that more than 52500 are actually there, given some parents would bring under 4's along.
I wonder if they would count, though i doubt it.