The family of Stacy Ann Peterson, the missing wife of a suburban Chicago police sergeant, thinks there is a good chance the 23-year-old is dead, but says the search must go on.

"She is giving me the strength and energy I need to push on," Peterson's sister Cassandra Cales told the Chicago Sun-Times. "I haven't really slept in six or seven days. I try to sleep, but I just can't."

Click here to read the Chicago Sun-Times story.

Peterson, 23, was reported missing Oct. 29, after she didn't arrive to a friend's house. Peterson is married to Bolingbrook, Ill., police Sgt. Drew Peterson, 53.

She was scheduled to meet with her divorce attorney the next day, according to CBS2Chicago.com.

The all-volunteer Texas EquuSeach Mounted Search and Recovery Team will be leading the search efforts today, Cales said. The group is equipped with divers, helicopters, horses, and dog and foot teams.

Plans are to search five "water areas" and two quarries, according to the Chicago Sun-Times.

Click here for photos.

Last week police searched wooded areas near the Peterson home as well as the residence, where they hauled away cars.

Authorities also reopened an investigation into the death of Drew Peterson's third wife, Kathleen Savio, who in 2004 was found dead in a bathtub at the age of 40. A coroner ruled the death accidental.

Click here for more coverage from MyFoxChicago.com.