"I wasn't going to let him starve and I didn't really care what people thought."
Although Moana and her family were in the shop for around two hours, she said she was only breastfeeding for half an hour.
"When I was walking around I did get a few stares, but I didn't mind what people were thinking while I was feeding," she said.
In her Facebook post, Ms Moana said: "Honestly mommy's have no shame if your babies are hungry feed them don't worry about what other a******s think because I wouldn't leave my babies starve that's for sure." (sic)
Moana, who's sons are five-months-old, said women should be proud to be mums.
"I posted the photo because I wanted mums to be proud to breastfeed in public and be proud to be a mum," she said.
The young mum said the response to her post, which has been shared over 400 times since Tuesday, has been mainly positive.
"Most of the comments have been positive and kind," she said.
"It's been so nice to have people sharing my post and getting the message out there.
"There has only been one mean comment but the person is young so probably wouldn't understand what was happening."
For the new mum, Ms Moana just wanted to get the message out to other mothers that they should not be shy.
"I wanted to tell mothers out there to have the confidence to do anything."