Monica Dickens first wrote Cobbler's Dream which is the name of a horse stabled at a sanctuary for horses called Follyfoot. That was really for young adults.
She admits that she caught on to the idea of a series for younger people so that horsey youngsters would keep buying the books. Her main characters Dora and Steve appear in Follyfoot and a few others such as Dora at Follyfoot. They were filmed for ITV. These books are aimed at younger readers but are still uncompromising in pointing out cruelty and neglect, as well as the hard work and cost of keeping horses, even those too old to be ridden. Miss Dickens knew her horses and when she wrote Cobbler's Dream, all her horse-owning relatives were scandalised and threatened to disown her for showing people what the horsey world could be like.
Monica was a debutante who got bored and started to work instead, then did various war jobs such as nursing and factory work. As a great-granddaughter of Charles Dickens, she was always destined to write. The American influence in the last Follyfoot book is because she met and married an American, becoming a navy wife based in Washington while keeping up her writing career for English publishers and magazines. Her own life story is called An Open Book with several earlier instalments such as One Pair of Hands and to my mind her autobiographies are better than her fiction.