I often see these little bird around. They belong to a group of birds known as white-eyes. It interesting that they have slightly different plumage depending which part of the country they live in and are found across Australia expect in the Northern Territories.
Silvereye measures 3.5 x 2.5 inches and is painted on 300gsm smooth Arches watercolour paper.
Many thanks to Patrick Kavanagh for the reference photo.