She was jailed for nine months on 31 counts of fraud, however, the sentence was wholly suspended for three years.
While her defence lawyer argued she was bankrupt, she was also ordered to repay A$1545 ($1647.63) to Coles and A$2070 ($2207.50) to Woolworths.
Ms Milner's court appearance comes just a week after news.com.au revealed Coles had decided to restrict the number of items able to be scanned at self-serve check-outs to 12, in a bid to combat ongoing theft.
The supermarket giant has also called on police to help crack down on rampant theft, which industry experts estimate to cost the company $1.1 billion ($1.17b) each year.
The move came after supermarket research body Canstar Blue found shoppers were more likely to steal at a self-serve machine, partly because customers were distanced from the human face of the business.
Supermarket theft is compounded by the ease with which self-serve machines allow shoppers to pass off more expensive fruit, vegetables and bakery products as cheaper products.
The "swipe everything as carrots" mentality was prevalent among young customers, who confessed to Canstar Blue that they had ripped off supermarkets at the self-serve.