She turns 11 in two days' time, which means that she will no longer qualify for the OceanKids event or a place in the squad.
Milne has been in the coveted training camp for the last two years and has set her hopes on making it a trifecta this season.
The up-and-comer credits much of her improved performance to her invaluable experiences at the two Jetstar training camps.
"I gave up the Junior Champs place, even though I have worked really hard for it, because I can try again next year but I can never be part of the fun of the Jetstar Super Swim Squad again," she said.
"The best bit for me was hanging out behind the scenes with Olympians. I also learned lots of streamlining techniques which have helped my swimming."
The camp held earlier this year included Olympic swimmers Moss Burmester and Melissa Ingram and coach Rick Wells.
Burmester said the camp is a great initiative for Kiwi kids.
"Identifying and nurturing swimming talent from an early age is crucial to their development," he said.
"It was great to see a number of the kids like Hannah attending the camp for a second time. They were a great bunch of kids and we really enjoyed getting to know them."
Hannah's mother Nicola said the swim squad was a great incentive for her training.
"I take my hat off to Jetstar for giving Kiwi kids like our daughter the opportunity to really develop their ocean swimming skills and their love of the ocean," she said. "Hannah will never forget her experience with the Olympians."
One of the highlights of her training camp experience was getting to know the other participants, a number of which Hannah and her mother (who joined her at the camp) have kept in touch with.
The girls quickly became a close-knit group, calling themselves the "Swim Camp Ninjas" and enjoying each other's company both in and out of the pool.
Ocean Swim Series event director, Scott Rice, said there was huge value in the camps early in a swimmer's development.
"As an ex-representative swimmer, I know how important those early training years are for developing not just skills, but self-confidence," he said. "That's what the Jetstar camp is all about - backing New Zealand's future swim stars right from the start."
There are 30 places on offer at each Jetstar Super Swim Squad which takes place in April at the end of the New Zealand Ocean Swim Series.
The fastest girl and boy in each age group at the OceanKids event gains entry to the squad.
The camp is a weekend gathering with New Zealand's best swimmers, and includes travel and accommodation, a range of surprises and specialist swim clinics.
To enter, children must be between 6 and 10 years old as of the day of the event.
Next up for Hannah is the State Harbour Crossing. She hopes to take part alongside her parents John and Nicola who are both long-time supporters of the swim series.
"We know the harbour swim can get choppy so unless the conditions are ideal we will not be letting Hannah in the water," Nicola said.
"We want her first harbour crossing to be a positive experience.
"It is a dream come true for John and I to have our only child sharing our love of ocean swimming and taking part in this series alongside us."
The Milnes may see a few famous faces along the way - All Black great Ian Jones will be competing in the series in 2014-2015 with two of his children, Flynn, 15, and Mia, 13.
The 47-year-old, who is the most capped All Black lock, has competed in the series for the past 10 years but this will be the first season he will be joined by his children.
"It is a chance to get outside and compete with like-minded people and be part of a great community," said Jones, who works for Sky Sport as a rugby commentator.
"I highly recommend ocean swimming as a fun form of fitness and an awesome challenge, and it's great to do with family and friends."
"Kamo" will be swimming in the 3.3km "I'm Going Long" distance at four of the events in the series.
Other distances include the 200m State OceanKids event and 1km and 300m "Give it a Go" options (depending upon the event location), as the series attempts to accommodate swimmers of all abilities.
State Ocean Swim Series
1. Bay of Islands Classic (Paihia), today
2. Harbour Crossing (Auckland), December 7
3. Capital Classic (Wellington), January 25
4. La Grande (Akaroa), February 15
5. Sand to Surf (Mt Maunganui), March 21
6. King of the Bays (Auckland), April 18
For more information or to register, visit www.oceanswim.co.nz. For more information on the Jetstar Super Swim Squad, visit oceanswim.co.nz/state-ocean-kids/
