Jaiden Lipschultz has been a big fan of “The Little Mermaid” since she was a little girl. For her senior year backpack, the Westchester high school student is celebrating her love for Ariel.

Local high-school seniors may be on the cusp of adulthood — dating, driving and applying to colleges – but they’re opting for very childish book bags for back-to-school. Backpacks festooned ...