The officer was on duty on Bourke Street at about 2.15pm on Sunday, August 31.
A beer bottle thrown by a man in the crowd struck her in the head, injuring her.
Police have now released images of two men they believe may be able to assist with their inquiries.
In the images, they appear to be wearing Australian flags as capes.
Anybody with information is urged to contact Crime Stoppers on 1800 333 000 or online.