Stephen Fitpatrick married Bridget Minahan 1870 at South Melbourne, Victoria, Australia

Bridget Minahan's parents were Patrick Minahan & Mary Keefe

Patrick was a gentleman who died 1888 in NSW, Australia.

Stephen Fitzpatrick was also later listed as a gentleman on his son Michael's marriage certificate so I think that he had plenty of help from his father-in-law Patrick Minahan. That's where the money came from.
 

Patrick Minahan's parents were James Minahan and Mary ?

I'm not too sure about any siblings for these people.