I have never met a woman named Sheila in Australia, nor have I met a man named Bruce despite the Monty Python sketch. Perhaps women are still referred to generically as sheilas in the country, but I have heard many people use the term humorously as a send up of ockerisms.
I suppose I ought to explain "ocker" as well. The stereotype of the beer swilling, uncivilised, true blue, aussie male of the outback and his thick accent rich in idiomatic phrases are known as ocker. Where the word comes from is anyone's guess. It originated in this century and the Oxford Australian Dictionary is unable to provide an etymology. I'm betting it has some sort of relationship to cockney rhyming slang as do a few other words. Onkas for instance is a word for fingers because in Southern Australia there is a district known as Onkaparinga which rhymes with finger.