In a sequel to My Sister the Meanie, more perils of being a younger sister. Jackie, 13, and her sister Sharon, 16, face a boring summer until an amusement park springs up nearby; there, Sharon finds a job, and Jackie finds a cute cowboy named Russell. But when Russell goes on a picnic with the sisters, he falls for Sharon instead--who already has a boyfriend (he's away at camp). Jackie suffers such indignities as watching her sister go out with two boys at once when her boyfriend unexpectedly returns, and getting teamed up with William, Russell's obnoxious little brother. When Jackie tells William that his brother is being strung along, a breakup ensues; but after the subsequent peace-making, Sharon has new respect for her younger sister. Although the story is supposedly set in the present, the girls always wear dresses, never watch TV, and live in a pre-suburban northern Virginia where teens go to the firehouse ice-cream social on a date. Clumsily linked events and unrealistic dialogue further detract from any sense of authenticity.