Sheila is a girl's name, but as a general term for a woman (eg. "She's an alright sheila.") only Australians use that. However, the male equivalent - "bloke" - is used in both Australia and the UK. "Billabong" is a specifically Australian word for ox-bow lakes in Australia. For example, an ox-bow lake in America or the UK is never called a billabong, even by an Australian speaker.

British people don't use them. The words "sheila" (a young girl) and billabong (an oxbow lake) are truly Australian.

Hi... yes you can use those...