Silke, it is listed in the ACT Census of Vascular plants as well as on our Flora list for Mt Majura but not for Mt Ainslie. So another tick for Mt Ainslie; well done Waltraud
There are about 10 other ACT records of Sheepweed, scattered mainly around central Canberra, the earliest record is from 1959. It is however a new weed to me.
Thanks for your comment Michael. I noticed the species at Majura paddock and area around our Fair planting site where I work regularly. Will take photos and register next opportunity.