Ward said she's speaking out now, for the first time to let other abuse victims know that they need to get out of unhealthy relationships.
"I think that all these people, all these men and women that are being abused, need to stop that violence," she said.
Peterson, who has gained about 20 pounds since entering prison, was in court Friday when a judge ruled that the statements Savio wrote before her death would be admissible in court.
Attorneys for Peterson, a former police officer in Bolingbrook, Ill., had sought to exclude from the trial Savio's writings in which she expressed fear for herself and her children.
Peterson is being held on $20 million bail after he was accused of murdering Savio, his third wife. The woman was found face-down in an empty bathtub in March 2004, her hair soaked with blood from an apparent head wound.
The medical examiner had initially ruled Savio's death a drowning incident but after the October 2007 disappearance of Peterson's fourth wife, Stacy, Savio's body was exhumed and reclassified a homicide after a new autopsy was performed.
Peterson was arrested in May and pleaded not guilty to the first degree murder charge.
Peterson's defense team has argued that he could not receive a fair trial in Will County because he is a 30-year local law enforcement veteran and because of the intense media exposure, according to the Chicago Daily Herald.
As Peterson sits in jail on murder charges for his third wife's death, his stepbrother could provide important information regarding the disappearance of Stacy Peterson.
Thomas Morphey, his stepbrother, said he helped Peterson move a large blue barrel from Peterson's home on the last day Stacy Peterson was seen alive.
The day before he helped move the barrel, Morphey said, Peterson confronted him. "He said, 'How much do you love me?'" Morphey told "Good Morning America" in March. "I said, 'I do.' And he said, 'Enough to kill for me?'"
Neither Stacy Peterson nor her body has ever been found, nor has the mysterious blue barrel.
The Associated Press contributed to this story.