John Cushing eventually got back together with Kristine Cushing, remarrying her in 2005, one year after divorcing Conlon. That same year California authorities ruled Kristine Cushing posed no risk to others.
After discovering Kristine Cushing was spending time with her sons, Conlon eventually hired an attorney to change their 2005 custody agreement so that her kids no longer have contact with Kristine Cushing.
Ideally, said attorney DeVallance, Conlon wants to make sure that if John Cushing continues to live with Kristine Cushing, his visitation will be in Oregon, where Conlon lives.
"And once it is confirmed she is no longer part of the children's lives he can have a regular visitation schedule in Washington," DeVallance told ABCNews.com.
It might sound like a reasonable request, but it is hard for a court to say whether Kristine Cushing could still pose a risk to the kids.
At the end of July, Conlon asked a court commissioner for a change in their custody agreement, but he ruled against Conlon, in part because her boys had not had any problems with Kristine Cushing, even after spending years in her company.
"She is a very sweet, quiet, gentle person," one of Kristine Cushing's fellow church parishioners told the Seattle Post-Intelligencer.
After the commissioner's ruling, Conlon took her case to a judge, and began speaking out to the media.
Judge Considers Whether Kristine Cushing Should Be Kept from Trisha Conlon's Sons
Judge Downing had been expected to rule during last Thursday's custody hearing.
Instead, he asked for more time to evaluate the case.
At the hearing, John Cushing's lawyer, Nancy Sorensen, argued there was no new evidence suggesting Kristine Cushing is a threat.
"The sole evidence presented by the mother is one tragic episode that happened 20 years ago," she said.
She added Conlon's son Sam, who is still living with John Cushing, is "excelling in all aspects."
Sorensen did not respond to an interview request from ABCNews.com.
Her current psychiatrist told the court she "does not present any danger to [Mr. Cushing's son]" and she "should have no problems living in the home with [him]."
Conlon's attorney, DeVallance, is of a different opinion, telling ABCNews.com, "If you harm children in any capacity, let alone killing children while they're sleeping -- their own children -- I don't care how long ago it was, there are consequences when you harm children and those consequences are for life."
The question remains: after decades of therapy, has Kristine Cushing healed?
"Could she recover? Sure -- people recover from mental illness all the time," said Stephen Morse, professor of law and psychiatry at the University of Pennsylvania, adding that some illnesses can also be successfully managed.
"The behavioral history is the really important thing -- how has she been behaving for the past 10 years."
That behavioral history is unclear.
Conlon says in September 2007 she received a call from a social worker for Children and Family Services in Washington's King County. It was then that she learned her ex-husband had remarried his first wife, and that her psychiatrist had "a significant concern regarding the boys' well being" and had reported the living arrangement to Child Protective Services.