This is either Eusynthemis guttata (Southern Tigertail) or Eusynthemis tillyardi (Mountain Tigertail). The former are mostly recorded south and west of your location, the latter more to the north-east around Sydney and the Blue Mountains. They are very similar and the most (only?) reliable way to tell them apart from photos is the shape of the yellow marking on the lower, almost under-side, of the thorax. This is unfortunately not visible in your photos, so it will have to be left at genus level ID. (I'll need to create a Eusynthemis sp. category...). If you see them again, Lisa, and can get photos from essentially underneath, it would be really interesting to know which species it is!
Oh, thank you so much. I’m always learning on this platform -I did not realise that photos of the underside were important for IDing. I’ll try for more angles in the future (although the chances of me seeing, let alone recognising, these dragonflies again are pretty slim!)