The 16-year-old St Crispin's School pupil had to wait until the penultimate day of the Festival to make her bow down under at the State Sports Centre in Sydney's Olympic Park.
And when she finally got going Pettit looked eager to make up for lost time as she scored 137.190 to finish the women's individual event just short of the podium in fifth.
But there was no such disappointment when she returned to action just hours later alongside Izzy Songhurst in the synchronised event, the pair claiming silver behind New Zealand.
Pettit, who is a member of Edgbarrow Trampoline Club, was adamant it would not get any better after her individual event but she was happy to be proved wrong.
"It was really good to win the silver in the synchro and this is by far the best medal I've won in my career," she said.
"It was the first time Izzy and I had done synchro together so it was a pretty good start. In the individual I wasn't expecting to finish as high as I did.
"I was already really happy because I surprised myself but then to go on and win the silver afterwards was just amazing and all in all it was a great competition for me."
And no sooner had the dust settled down under Pettit was already looking to the future, adamant it looks much brighter after getting 2013 off to the best possible start.
"I'm really confident about this year now after starting 2013 like this, it's going to be a good year," she added.
"We have the World Age Group Championships in November so I just want to work towards that and this gives me the confidence to do well again."
The British Olympic Association prepares and leads British athletes at the summer, winter and youth Olympic Games. It works in partnership with sport National Governing Bodies to enhance Olympic success and is responsible for championing the Olympic values. www.olympics.org.uk