Representing South Lanarkshire, Evi won the 11/13 years 200m butterfly in 2mins 40.05secs to shatter her previous best, with silver medals in the 100m breaststroke and 200m IM and bronzes in the 100m butterfly and 400m IM.
Millie McArthur reached the final of both the 200m backstroke and 100m freestyle and became Lanark’s fastest ever female long course 50m freestyler with 28.75secs.
Millie was also part of four South Lanarkshire relays which secured three fifth places and one sixth place.
The club’s other finalist was 14-year-old Craig Shaw who was sixth in the 200m breaststroke and seventh in the 100m breaststroke.
Lanark’s other three representatives were all in butterfly events. Abbie Barnstaple (15) and Cameron Bruce (17/18) both posted personal best times while Euan McLeod (17/18) was just outside his best ever mark.
Abbie’s 50m butterfly time was only 0.11 seconds outside the Lanark club records.
Lanark coach Karen Kelly said: “Evi’s results were excellent and just reward for her commitment and dedication in the training environment. Millie has battled with breathing problems and did well to reach finals and break a club record.
"Craig, in his first nationals, exceeded all expectations and the three butterfly swimmers put in some solid swims.
"Our Lanark pool has been closed a few times with roof problems and we are indebted to our friends at Larkhall, Hamilton and East Kilbride clubs who generously offered pool time to our six Scottish National Age Group Championship swimmers.”