Probably this mob.
Australian Women Pilots` Association They say as much about their membership numbers on their website as does that "organized organization" you mention.
I draw your attention to post # 113 Annual report to ASIC.
Receipts from membership fees: $97,744.00 Divided by $145 average but not including non natural non voting members, non voting juniors, associate members etc. comes to 674 members. This despite the information given to Auditors there were 2,588 members?
Only members with full voting rights should be claimed. Perhaps they are claiming "lapsed members" which many are unless those members resign in writing. (read the articles of association).
Take note: they do not represent me!
Even if you add the two totals together and divide by two for a wild average there are still 1631 which is still a bit shy to be claiming to represent all of GA.
I estimate the PPRune posters networks who have made submissions to both The Senate and this enquiry have more combined members.
But what would I know?