Adelaide: Augusta?

The Rundle Mall pigs, officially 'A Day Out' by Marguerite Derricourt, named by the public when unveiled in 1999: there's Oliver in the bin, Horatio sittin' pretty, and Truffles looking a bit sheepish but my main concern is, where is Augusta?  She should be smiling and trotting.  How could I miss her?  This requires further investigation of the scene.