I'm guessing they wouldn't have a place for her anyway with the screenplay that was written. Though, i absolutely loved her in the first one.
http://i43.tinypic.com/vo0wb4.jpg
http://i44.tinypic.com/308l8o6.jpg
It wasn't her call. Universal didn't want to shell out the money for the stars of the first movie (outside of Alex Vincent and Brad Dourif) to return.
Catherine Hicks was even on set for the filming of 2 (she's married to Kevin Yagher) when she brought her husband his lunch.
All New Season:
http://www.fictionpress.com/s/3063383/1/Omega-Guardians-Season-2