This one would be a new species, there aren't any currently described species of Idiosoma in or near Canberra. This genus is very uncommon in this region (at least according to the data available) and every sighting is a bit more helpful. If you find another one, it might be a good idea to collect a specimen for future research
@AaronClausen yep, a brand new species for Australia. Undescribed species of mygals are all over Australia, but it's always cool to find one so close to home