The Millfield-based Barracudas protege has earned a place on phase two of Swim England’s talent programme, giving her passage to her first national event camp in December.
Tostevin has also been selected to represent the South West team at next February’s Lisbon International.
This follows a successful outing at the National County Team Championships at Ponds Forge, Sheffield, featuring 900 swimmers from 36 different counties in two different divisions.
Tostevin had competed in the heights of Division One, representing Somerset in the age 16/17 category.
The 16-year-old’s first success of the meet came when she stormed to a great personal best of 1min. 2.17sec. over the 100m backstroke.
Not only did she improve her own island record from the Gibraltar 2019 NatWest International Island Games, she also managed to touch in second to clear winner Honey Osrin of Devon.
Competing in the relays to a packed house and fun atmosphere, Tostevin again produced an excellent performance.
She started off the 4x50m medley relay with a fine backstroke leg of 28.91, dipping under 29sec. for the first time after coming close to that mark in Gibraltar.
This placed her fourth individually, although her team could only muster 10th amid the great competitive depth.