The Grass Harp (1995)

After his mother's death, Collin Fenwick goes to live with his father's cousins, the wealthy, avaricious, and controlling Verena Talbo, and her compliant, earthy sister Dolly. When a city slicker comes to town and convinces Verena to market Dolly's locally-famous tonic, Dolly finally gets some backbone, refuses to divulge the formula, and heads for a tree house with Collin and Catherine, the loyal maid. Verena, who has most of the town in her pocket, sics the law on the renegades. Dolly, Catherine, and Collin find a supporter in a retired judge, Charlie Cool, who's attracted to Dolly. Will Verena's venom win out? And what about that city slicker?