costumes, halloween party, bobbing for apples

Sexy witches?

Full on Exorcist-level possession/body-snatching

You could always have your characters discuss the pros and cons of sex with various monster-types.

Tiffany as a succubus

Ghostly girl versions of the ladies?

Carnival attraction type of haunted house to show how your girls express fear? Scenarios I imagine include: Brittany screaming from paper bats on strings that fall from the ceiling. Janette shakily telling Selene it's all just a show, nothing to be scared of, while Selene is giggling and enjoying seeing her older sister's fear. Amy embarrassingly standing over a broken wooden cutout of a ghost with her sword out and arms extended post-swing.