Coming from the UK, she'll probably think it's warm.... although June is what Aussies call winter!
There will be some rain.... not heavy storms, but periods where it drizzles down all day. Nights will be crisp in NSW, less so as she travels north into Queensland. Some days will be so gloriously clear and sunny that she will think this is the best climate in the world.... but, still, she will need to be prepared for the other kind, too.
Oh, dear, that's really not much help, is it? What I seem to have told you is to be prepared for everyth kind of weather there is! Maybe the next poster will be more concise!