Re: Australian Turners.
I too have a Louisa Turner ch.9 June 1844, from Esher, Surrey, England.
You mentioned siblings - do you know their names ?? My Louisa is one of 8 children, and her parents are Samuel and Louisa.
I don't know if they came to Australia, as I've only just started on this line. I think there would be a good possibility, as others in the extended family of this line did come to Australia.
Let me know if you think there may be a connection.