Felicity: An American Girl Adventure 2005 on netflix

A pre-American Revolution Virginian girl’s love for the outdoors leads to the friendship of a lifetime. Felicity loves horses, and though her parents plead with her to remain indoors, she yearns to ride the open plains. When Felicity comes into contact with a beautiful mare which has suffered at the hands of its callous owner, she takes it upon herself to care for the creature.