Where were you married, Winnie? I think that is a major factor in how difficult it is to change one's name. If you were married overseas then you'll need to get the thingo from Births, Deaths & Marriages because the name change hasn't been recognised in Australia. Happened with my mam - all her documents (passport, birth certificate, marriage certificate) were stolen a couple of years back, and because she was married in NZ she had to get the thing from here to say that she had changed her name. Or something. I'll ask her next time I talk to her. Took a few months to get everything sorted out.
Then again, if you were married in Australia then I assume there wouldn't be such an issue.