Someone uploaded three photos of it on the Australian Bird Identification Facebook group wanting to know whether it was a paradise shelduck or a South African shelduck.He saw it, so I assume he knows what it is...
Where is the "South African Shelduck" coming from? The two species do not look similar enough for there to be any confusion.
Everybody there is still discussing which species it is but the general consensus is a female paradise shelduck.