I thought the leaves were too rounded for C. aristata and it seems late flowering. But it seems the best fit. C. glycinoides would probably have finished flowering by now.
I have added two photos with a background grid of 5mm. @Tapirlord I have looked at your recent sightings of C. glycinoides and the leaves look the same. It seems that glycinoides is summer flowering as well as spring. ALA shows some in north Canberra, though these could be ANBG escapes.
Those other photos definitely eliminate Aristata. So I reckon it is C.glycinoides, a very interesting sighting of a species that I didn’t think occurred in Canberra. My sighting of it is over and hours drive away in Bungonia national park. I wonder how it got here.