Female Baudin's also has a whitish bill.
The Slater field guide illustrates the females of both species, whereas the Simpson & Day and Pizzey field guides illustrate only the female of Carnaby's. Presumably this is to save space on the illustration plate. The text accompanying the plates, in both these field guides, does indicate that both Carnaby's and Baudin's females have pale (Simpson & Day) or whitish (Pizzey) bills.
Based on what I can see of the bill in the photos here, and comparing that to what I see on the Carnaby's that come to trees near my home, I'm inclined to think that the photos also show female Carnaby's Black Cockatoos.