Aquamarine

Two Florida seventh-grade pals (Emma Roberts and Joanna “JoJo” Levesque), spending their last summer together before one of them has to move to Australia, find a mermaid (Sara Paxton) in their swimming pool, who speaks English with a flawless valley-girl accent. Adapting Alice Hoffman’s novel, writers John Quaintance and Jessica Bendinger fiddle with the plot, importing elements from Splash (the mermaid’s temporary legs) and Disney’s The Little Mermaid (the cranky sea-god father, here spoken of but never seen), along with the queen-bee villainess from teenybopper movies like Mean Girls and Confessions of a Teenage Drama Queen. All those movies are better than this one; it’s silly and trivial but harmless enough for undemanding teenage girls, and Roberts and Levesque make a vivacious team.