Achieng Ajulu-Bushell last represented Kenya at last summer's World Championships in Rome after which she decided to switch nationality, requiring a year's eligibility period before she could swim in British colours.
The 16-year-old will be available to British selectors from August 1 meaning she could make the teams for both the European Championships in Budapest and the Commonwealth Games in Delhi.
Ajulu-Bushell is the African record holder in the 50m breaststroke having eclipsed the mark set by former double Olympic champion Penny Heyns.
Born in Manchester to an English mother and Kenyan father, Ajulu-Bushell moved to Africa before returning in September 2007 and enrolling at Plymouth College – along with Daley – and representing Plymouth Leander.
She said: "I was born here, I have a British passport, my mum is English. Having moved back here, and once the choice was presented to me, I felt more English. I'll always have that heritage, always have that background. I guess it's the best of both worlds."
Robert Bale claimed the 200m freestyle title in 1min 47.82secs ahead of Robert Renwick and defending Commonwealth champion Ross Davenport.
Amy Smith was a clear winner of the 50m butterfly title in a personal best of 26.88 ahead of Ellen Gandy and Louise Pate.
Double World Championship finalist Lizzie Simmonds, 19, of
Beverley eased into the 100m backstroke final.