Her next gold came on the last night with a dominant victory in the 100m butterfly.
This time Chemis led from the start to win in 1min 10.75sec. This was well under the qualifying time for the national age-groups and a best time by more than four seconds.
Chemis was also in superb form in freestyle events, collecting two silvers and a bronze.
She also helped the regional medley relay to second place with a swift 50m butterfly.
John Paul College student Josh Ensor produced a stunning victory in the boys' 15-years 200m butterfly. He stuck to his race plan to trail the fast pace-setters, then picked up speed in the second half of the race.
His winning time of 2min 28.75sec was a big best time and well under the qualifying time for the national age-groups.
Meanwhile, Joe Nagera, 13, enjoyed great success in his backstroke events.
Nagera scorched through the 50m backstroke to take the silver medal in a best time of 32.22 seconds.
He repeated the feat in the 100m backstroke with a beautifully paced race to take his second silver with another best time of 1min 10.37sec.
Ana Nagera produced a great string of performances in her signature breaststroke events.
Her best result came in the 13-year-girls' 100m breaststroke to place fourth with a best time of 1min 23.33sec. She also placed fourth in the 200m breaststroke and 50m breaststroke, with two gutsy efforts.
Head coach Alastair Johnson was delighted with his team.
"Despite only having a small team, we have definitely punched above our weight. The athletes have shown tremendous resolve and effort and deserve their success," Johnson said.