
Certified GKH Gardening Expert
Although I wouldn't know from personal experience, since we don't have them here in the US, but there are several sources that state these will leave Junipers alone.
If they are anything like our deer here, that won't mean much. Our deer will eat anything, even if it is labeled as deer resistant. Your wallaby population may be the same way. Most sources say that there is nothing to worry about with Junipers, though.
This article can help in the meantime: https://www.gardeningknowhow.com/plant-problems/pests/animals/keeping-wallabies-out-of-gardens.htm