Little House on the Prairie - Season 3 Episode 2 -

When Nellie Oleson is seriously injured after falling from Bunny, a horse that used to belong to Laura Ingalls, Nellie's mother blames Laura for the accident and orders the animal destroyed. But Laura secretly steals her still-beloved Bunny away from Mrs. Oleson's vengeance and resigns herself to the penance of waiting hand and foot on a demanding, bedridden Nellie.