Maybe, just possibly it could be a young Sambucus nigra (Black elderberry) which I think grows in your part of the world. Definitely has leaves growing in threes at the end of the stems, but more usually has a further two lower down the stem when older, see :-
https://allrareherbs.com.au/product/black-elderberry-plant/ If so this is a handy addition to the garden, berries have all sorts of properties, flowers make a great wine.
There are dangerous leaf look-a-likes, so best plan to wait for a flower and/or fruit appearance.
Edit to add: does anyone have an image of the leaves of an older plant for comparison - elderberry doesn't grow near me.