Store manager Shelley Winika was away at the time, so Ms Chaney took the items and later told company owner Lydia Luo, who she said noted the purchase in the diary.
Ms Luo denied noting the purchase of the items.
When Ms Winika returned four days later, she asked Ms Chaney whether she had taken a T-shirt from one of two boxed sets while she was away.
Ms Chaney asked if there was a problem, and was told Ms Luo had a problem. She was fired at a disciplinary meeting the following day.
Her dismissal letter said the removal of items from the store, without permission or the knowledge of any staff, constituted serious misconduct.
The letter did not specify the removed items, but only one of the two T-shirts was raised at the meeting.
Ms Chaney raised a grievance with the ERA, claiming lost wages and loss of paid maternity leave for her daughter, who was born in April.
She also claimed compensation for hurt and humiliation, saying her dismissal caused considerable financial stress because she was pregnant and a single mother.
Ms Chaney said she was unable to buy items for her baby and had to undergo blood tests and extra midwife appointments due to the stress of being dismissed.
The ERA found no evidence Ms Chaney had taken the T-shirt without intending to pay for it. However, it found Ms Chaney's failure to record the T-shirt purchase contributed to the situation that gave rise to her grievance.
The ERA ordered Surreal to pay $12,147.40 in lost wages, including parental leave, and $5600 in compensation. The company was also ordered to pay $1821.56 in costs and filing fees.