Simons was a member of the historic Under-17 Australian Sapphires team that won gold in 2016 and she also represented the Under-19 Gems at the FIBA World Cup last year.
While she was unable to recreate the feeling at the Under-19 World Cup, the Gems' sixth-placed finish did not reflect their overall performance as they finished with a 4-3 record while their defeats came at a total of just nine points.
Simons averaged five points per game at that campaign as a 17-year old while scoring a tournament-high 17 points in a group game against Mexico which included 3-5 three-point shooting.
"Winning gold with the Sapphires is one I will never forget," said Simons.
"We were the first team to ever beat the USA at Under-17 level and then to win the gold medal was so special. There were so many learning experiences to take away from it as well like playing in front of such big crowds and against bigger bodies and girls who are very good at basketball."
Rees, meanwhile, won gold at the Under-17 Oceania Championships last year which is the precursor to the Under-18 Women's Asian Championships which will be held later this year.
Australia swept the tournament and Rees showcased her ability to influence all areas of the court as she finished ninth overall for scoring with 14 points as well as seven rebounds, 2.4 assists, 2.2 steals.
"I loved wearing the green and gold," said Rees.
"I got to see a different part of the world and to play against other countries was awesome and a great experience."
Despite those international ventures, Simons and Rees both agree that is a separate, special feeling to play for South Australia and they are each featuring in their fifth Australian Championships this year.
"It's a great feeling to represent your state," said Rees.
"I'm so proud to be here playing with girls I've grown up playing basketball with. Growing up, you want to reach the pinnacle and playing for SA has been a great step for me towards playing for Australia and hopefully one day I can reach the Olympics."
"There's nothing like representing SA," concurred Simons.
"It's your home town and there is so much pride and culture in SA so it's always great to wear the red and blue."
In a rare event, the entire South Australian team at this year's Under-20's consists of bottom-agers with seven members of the side still teenagers.
"We are all young but we are fast, aggressive and athletic too," said Simons.
"We have played together for a long time so it's always enjoyable to get on the court together," added Rees.
"We know what everyone else is doing on the floor and where they are moving to which helps your own movement as well."
Midway through Day 4, SA owns a 2-2 record with wins over Tasmania and Western Australia but they have been unsuccessful against Queensland and New South Wales.
Simons is averaging 13.8 points, 5.3 rebounds, 4.3 assists which included a near triple-double against WA when she collected 18 points, nine boards and seven assists.
Rees is also controlling the front court with 11 points and 5.8 rebounds per contest while patrolling the defensive end of the floor with an average of 2.5 blocks.
With two games remaining, they still have a chance to reach the top two and play off for the gold medal while a third or fourth spot finish will see them play for the bronze medal on Sunday.
However, Rees is not worried about the outcomes and knows that the team only needs to concentrate on their own performance.
"It's important that we focus on our goals and stay true to our own game," she said.
Keep up to date with all the results and LiveStats from the 2018 Under-20 and Ivor Burge Championships here.