"I cannot actually remember whether I won, but I probably did," she says. "I was just starting to get quite good by then."
Kath's experience with the newly formed Brierley Hill Amateur Swimming Club would change her life, setting her on a career in the sport, and several European titles to boot.
And 58 years on, Kath was reunited with a number of the other youngsters of the "swimming 60s" at a special club reunion in Wombourne. Kath and her old friends also met up with their old swimming coach, 96-year-old Betty Howchin, for a separate, informal reunion in Kinver earlier in the day.
Kath, or Katie as she was then known, joined the club in its first year at the shiny new pool, which itself had only opened four years earlier.
She took to swimming like, well, a duck to water. Encouraged by her coaches, she very soon found herself taking part – and winning – many competitions. She also made a number of close friends in what would become a tightly knit group of people with a shared interest. And then they grew up, the responsibilities of adult life taking them in different directions.
"We swam together for about four years, and then we went our separate ways," says Kath, now 70, and living in Kinver.
"The first coach we had was Ada Preece, her husband Jim was the manager of the baths."
In February, 1965, the club also took young Katie and seven of her friends on a three-day trip to the pool at Crystal Palace in London, where they received training under the supervision of Olympic coach Mr A D Kinnear.
For Kath, the values of discipline, learning and camaraderie would shape her life as she embarked on a career as a PE teacher. Sharing her passion with the young, she taught PE at Buckpool School in Wordsley for 34 years, where many pupils followed in her footsteps by joining Brierley Hill Swimming Club.
And in the late 1990s, Kath decided to follow suit by rejoining the club where she had learned so much as a child.
"I dug back into my past when I was 46, and rejoined the club," she says.
"I didn't expect to be back swimming, but it was a brilliant second opportunity, which ended up with me having some amazing times."
For most members, the end of Brierley Hill Swimming Club came with the closure of the swimming baths on January 1, 2006.
"It did continue for a while at Dudley Leisure Centre teaching children to swim, but it wasn't training them for competitions," says Kath.
The reunion on October 21 had been organised by a member of the club from a different era, but Kath was surprised by how many from the early days turned out.
"We hadn't seen each other for well over 50 years, and they are probably some of the nicest people you would ever meet in your life," says Kath.
"I really liked them as people, it was good fun, and I was amazed at how healthy they all were."
Another reunion has already been organised for next year.
While the club is no more, Kath's love of swimming hasn't diminished, and she won two gold medals at the European Championships held in Rome this year, taking top spot in 70-75 age group for the 50m back crawl and 200m back crawl.
About 120 members spanning several decades turned out for the celebration at Wombourne Civic Centre last month, including many of Kath's former pupils.
"I knew a few people from different years," she says.