I am on ereader, cannot do live links, but on blake1 thread back on Australia board in 2014, one of the most experienced Australian researchers helped our OP on this same question, confirming that there are no passenger lists for voyages from Sout Australia to England to get the family back to England. I am sure that that research provided just five years or so ago, by Cando, would have been undertaken using her own resources and not reliant on commercial websites... I am at a loss to understand why this new thread is on the beginners board ...
PS, gold fever cannot occur until after the news of gold discovery has reached the broader communities. Gold discovered in NSW and Vic colonies mid 1851. Rushes need shiploads of migrants, so a person arriving in South Australia prior to discovery of gold cannot have been motivated to migrate by chasing gold ... perhaps a reason for migration to S.A. could be to start a life in a newly established convict free society....
JM