Simmons was born in Vancouver, British Columbia, one of three children (one younger brother and an older sister) and has been a natural performer since the age of two. Her first movie role was as 'Its' first victim in the horror movie It (1990) in which she played Laurie Ann Winterbarger. Her most recognizable roles are in movies such as Final Destination 3 (2006) as Ashley Freund, and also in other movies like Carrie (2002) and Monster Island (2004). She has also guest starred in episodes of Smallville and Supernatural.