When she helps Magic Spirit, Tilly meets Angela, who owns a stables called Silver Shoe Farm.
Angela invites Tilly to spend time at Silver Shoe Farm, learning about riding, training and caring for horses.
Each title in the series tells a new story about Tilly's adventures with horses and ponies that she comes into contact with, as well as her continuing relationship with Magic Spirit.
The series is also linked with a continuing story about Tilly's background and birth, the only clue to which is a bracelet made of horsehair.
As well as the fictional story, each title also contains a tips section with expert advice from Pippa Funnell on all aspects of horses and ponies.