Cohen's fantastic as Maggie, really doesn't get enough to do IMO, and did a great job on Supernatural as Bella; I still despise what the show did to her.
Yes, her character got the boot way too fast. After just... what was it... six non-consecutive appearances in Season 3? She was a lot of fun, and deserved a much longer story arc. She probably would have been given one if fans of the show hadn't started throwing hissy fits over how her character was constantly screwing over the show's two leads. How dare she!