Taking a three-shot lead into the final round at the Home of Golf, Darling (15) held her nerve to card her second even-par round of the week to finish four under for a final total of 209 at Eden Course.
Darling, who plays at Broomieknowe Golf Club in Bonnyrigg, was the only player in the entire field to finish under par and emerged a convincing winner by six shots, finishing with a birdie.
England’s Ellie Gower, who was two under through 12, took an eight on 17 and ended in third place on three over, a shot behind runner-up Australia’s Isabelle Simpson.
It’s another title to her name for Darling, who was crowned the inaugural British Girls U16 champion last year, and is a two-time Scottish Girls Amateur Champion and the Scottish Girls Champion of Champions in 2017.
After her success, she said: “I was really steady out there today and went on a bit of a par-run, but I think that was worth it. Ellie was holing quite a few putts and had me worried at some points, but I stuck to my game plan and I’m just really happy to come away with the win.”
It gives Darling a huge boost as she prepares to take part in the Helen Holm Scottish Women’s Open Championship at Royal Troon on Friday, which will also count as a qualifier for this year’s PING Junior Solheim Cup.
Darling added: “It’s a women’s event so it will be stepping up another level, but I’m definitely happy with where my game is and I’m ready to take on the challenge, and hopefully I can come out with a good finish at the Helen Holm.”