Workplace Law - Case Study Analysis

Question
Mr and Mrs Donegan own a pharmacy. The pharmacy was busy so they decided to employ 19-year-old university student Elizabeth Matthews. Elizabeth commenced work at the pharmacy in December 2003.
Mrs Donegan: "We'll pay you $12 an hour. There won't be any set hours but we'll probably need you after university every day and on Saturdays. Ok?"
Elizabeth: "Ok."
Mrs Donegan: "We'll give you your earnings in cash on Thursday nights. You know, it's up to you if you want to speak to the tax office about deducting tax from what we give you. …