Kayla Stra was born in Australia, where she launched her career in horseracing prior to moving to California in 2008. From a very young age, Stra was interested in horses, having talked her parents into buying her a pony when she was eight years old.

During her late childhood and adolescence, Stra worked at racing stables and eventually bought her first horse a Thoroughbred named Gurtie, which she trained on her own for picnic races (unregistered race horses) before getting her certificate in racing.

She acknowledges her first trainer, Ray Moore, as someone who has had a strong influence in her life. Moore taught Stra how to be a horseman and how to communicate with horses by reading their body language and having a keen feel for what they're thinking. Stra credits John Letts as one of her mentors for his outstanding jockey career, having won three Melbourne Cups and hundreds upon hundreds of stake races.