Ancestry has 11 images of passenger list for the Osterley on this sailing - if you use the 'browse' option to find them use London as the arrival port rather than Plymouth.
She obviously stopped at Plymouth first - (and Tilbury) but London was her final destination - and that is how Ancestry have her indexed
She appears to have embarked passengers at Brisbane, Sydney, Hobart, Melbourne, Adelaide, Fremantle, Colombo, Port Said, Naples, Toulon and Gibraltar
Hope this helps you find it