It is also possible that Bridget married again to a Patrick CASEY in Adelaide in 1860. I dont see any children from them. He may have died in 1866 but who knows if you don't buy a certificate, but even that may not have the right information on it.
Genealogy is not an exact science, it is painstaking in the extreme sometimes

You do need to get the facts, not the supposition, so buying certs is probably the only way to ensure you have the right person.
Neil