Ms Petrie, 34, is now waiting with bated breath to see if she qualifies for the Special Olympics to be held in Tasmania in 2022.
“I've done my best and I just have to wait and see now,” she said.
“All the different sporting teams travel together to the Olympics.
“I like meeting the other teams, it's so exciting when you get to the airport and see everyone.”
Ms Petrie competed in four races, placing fourth in 50 m freestyle and sixth in the relay.
“I accidently got disqualified in the backstroke because I was just so excited, I started before the gun went off,” she said.
Ms Petrie has been swimming since she was in her early 20s and is a member of the Echuca Swim Club.
She trains twice a week for a few hours.
Her coach Shirley Milgate encouraged her take part in the qualifying round on May 1 where about 100 people competed.
“My family are really proud of me and came and watched me compete,” she said.
If successful, Ms Petrie will be looking for support to help pay for the travel expenses of attending the Special Olympics.