Very small, active - ie I couldn't find it resting. Perhaps Zacorus carus but not sure the palps match? In Moths of the ACT.there is a white Microbela allocoma (p67) but I can't fins a white one in BOLD, LBH or iNat.
That depends if the size = body length or wingspan. Ian McMillan's blog for example CRYPTOLECHIA LUTEOTACTELLA ".......Length of the body 4 ½ - 5 lines [9.5 – 10.6mm]; of the wings 13-14 lines [27.5 – 29.6mm]......." (Walker 1864 Source http://xyloryctinemothsofaustralia.blogspot.com/2010/06/xylorycta-luteotactella.html This white Xylorycta sp moth would fit in the size range for body length. I am NOT saying this moth is this genus necessarily, it is an example.