The CB400 is a fantastic bike for both a new rider, and a smaller rider. When I took my test, they were the bike that the test centre used.
They have a low seat height, are mechanically pretty solid, and cheap! (Well, they are here, but I don't know about Aus.) At 5.9 you will be more than capable of safely handling one.
I don't know if they import them over to you, but a GS might be good option. That is a Suzuki GS, rather than the BM, low power, low insurance, low seat height. Quite similar to the Honda, also used by a lot of test centres as well.