The New Best Friend

Jess, Mel, Sam, Amber and Cara are lucky enough to be able to spend as much time as they can with their favourite ponies at Vicki's Riding School. Grooming, sweeping the yard, even mucking out is fun when you love ponies as much as they do.
Amber and Jess have been best friends for ages, but their friendship is put to the test when Jess's school friend, Lauren, joins the stables. Lauren is loud and bossy and taking Jess away from Amber. But why can't Jess see that?
There's a sponsored ride going on and all the yard girls are excited about it. But when Lauren says she's coming too there's going to be trouble.
Will all the girls get to take part? And will Amber and Jess ever make friends again?