@Aryyy unfortunately not everyone has a great support system and people to be able to watch their children for them !
There is an FB group called Southern Highlands Mums & Dads and I often see people looking for sitters posting there and getting responses from available sitters, or recommendations for good sitters from other people in the local Community. You could also try care.com, it shows their credentials and references etc.
I'm pretty sure there is a nanny/babysitter company in the highlands or if on fb just ask may be able to help I know a few people have luck on there my friend is also a baby sitter