Australia is nothing like Europe. I think Europeans are more inclusive and the landscape (building, school, cities, towns, even drinking culture) are structured to be close-knitted. An abroad student will feel very welcome. And it’s a chief reason why lot of people love going to Europe and is a popular destination for abroad students.
Australia is the polar opposite in my opinion. It’s a very xenophobic culture, quite superficial (not that there’s anything wrong with that), very cliquish, and more distant. If your kid is going abroad there, chances are she will be most likely just be making friends with other student abroad kids. Sydney and Melbourne are very alluring cities, but just be aware that is in no way as welcoming as other cities.
This is speaking as someone who has encounter experience studying abroad in Australia, and have traveled to both continents there after. I would only recommend Australia to students who are prepared to be independent.