White pattern virtually the same as Male Oxycanus belista shown on Butterfly house; More pink than brown; Antennae short and thin, segments like the tops of golf tees, no projections so maybe a female, a bit like Oxycanus australis.
Given the key to antennae provided by Moths of Victoria I think the second image shows a good match to a female O. australis, Sotherhen Oxycanus, although I see no reference to other ACT records of this species online -althugh there are coastal NSW records at this latitude. The predominant dsitriburion for this species is Victorian and Tasmanian. Extension of the range for O. australis to include the ACT seems plausible on ecological grounds. O, belista is less likely I think given that species Queensland distribution. The suggestions of pinkish colouration would fit O. australis too.