Ashley was supposed to have gone on a date with Shaggy, although she was kidnapped by the Ghoul Girl before-hand. Niki threw garbage at Shaggy due to her strong hatred towards him. Niki was also thought to be the Ghoul Girl, until it was revealed that it was really Ashley behind the scheme, as she wanted to date him without her sister getting in the way of things.
After Ashley had been sent to prison, Daphne talked with her and helped her realize that now she had no reason to hate Shaggy anymore. Upon this discovery, she was dragged underwater by the Fish Monster, along with Daphne.