Diamond Firetails are occasional visitors to the neighbourhood. They feed on the ground usually on the margins of open woodland. A small flock will turn up, stick around for a while then move on. In winter flocks may coalesce and transform a familiar place. Next time you visit you may not find any.
I found this group on the outskirts of Maryborough where irrigated farmland abuts some Box/Ironbark Woodland. There were some youngsters among the adults.