McCully has been working with the woman, whose baby tested positive for the drug at birth, for two months.
"Mom, you need to understand you don't have much time," the judge says, telling the woman to check into a treatment facility, stay clean and learn to be a parent.
McCully has given that order hundreds of times in 23 years as a juvenile judge - and then watched as it proves too much for parent after parent.
Yet, she refuses to see her job as an exercise in futility. Each new case is an opportunity to help salvage a family, to rescue a child.
"You know every day when you go to work you might make a difference," McCully says, though it's hard to know. "Successes don't come back to court. Failures do."
McCully became a judge at age 29, the youngest person ever appointed to the Utah bench. Today, as one of 27 juvenile judges, McCully is the force behind several innovative approaches to juvenile justice that she believes hold promise for helping families.
McCully comes from the kind of family that so many children she sees in court lack: tight-knit, tradition bound, rooted.
Her father, Jim Peacock, was a principal, county commissioner and government relations director for education and oil industry associations - public service that showed McCully government in action and provided a compass for her own future.
Her mother, Barbara, was a homemaker who, McCully says, kept her and five siblings in line.
The family has gathered at Indian Creek in the Manti-LaSal National Forest on July 4th for 40 years. The Saturday before Easter is spent at the San Rafael Swell, where the extended family - totaling 70 some years - congregates for an annual egg roll.
"There is something good about the ritual of those things that keep family together," says McCully, 52.
By high school - she attended Emery and then Hillcrest High - McCully had settled on becoming a lawyer. She earned degrees in political science and English at Brigham Young University, then a law degree at the University of Utah.
As a college sports devotee, her loyalties are undivided. "I'm a BYU fan," she says.
When McCully joined the Utah Attorney General's Office in 1978, she became the second woman - and only woman at the time - on the state's legal staff. But she didn't consider herself part of the Equal Rights movement then underway.
"I always considered myself a lawyer, not a woman lawyer," McCully says.
She made an impression with her work on social services cases and contributions to a task force that created the state's youth correction program. In 1983, then-Gov. Scott Matheson named McCully to the bench.
Today, it amuses her to recall grilling judges Red Garff and John Farr Larsen about the nuances of hearings and decision-making, and the court-room scripts she wrote to use as she gained expertise and confidence.
In 1986-87, McCully served on a gender and justice task force, an experience that, along with her daughter's birth, shifted her perspective.
"It made me aware how important it was for those of us who are women in the profession to be mentors and pave the way," McCully says. She also learned how custody and support issues often place a disapportionate burden on women.
She gained a personal understanding of those dynamics, too. McCully's marriage crumbled when her daughter was 9.
"Even with more family support and financial resources than my clients have, it is still very difficult to make that work," she says.
McCully, 52, has a Mona Lisa-like smile that tends to soften the edicts she must give and belies the frustrating stories so typical of juvenile court.
She chain-drinks Diet Coke. Her finger nails are perfectly painted every Tuesday night, an admitted indulgence, in seasonal shades that seem lifted out of the paperback romance novels she devours.
Rootbeer Float each fall. I'm Not Your Waitress, a Christmasy red. It's All Greek to Me or All Rose Lead to Rome for spring. And Pompeii Purple, which is actually a hot pink, in the summer.
McCully's office is cluttered with code books, stacks of journals and heaps of paper. Sacks of stuffed animals, given to children at adoption proceedings, occupy a tan coach.
A plaque commemorates McCully's stint in 2004-05 as president of the National Council of Juvenile and Family Court Judges. Judge Kimberly Hornak, a colleague and friend, says McCully is considered a national expert in juvenile law.
"It is not uncommon at all," Hornak says, "to have judges wander down to her office to ask for her opinion on cases, and other judges in the state as well."
McCully fights a sense of helplessness at the stream of broken families that flood juvenile court. It helps that, once in a while, she learns there are happy endings.
"Just today, a woman asked the bailiff if she could come in and see me, the judge said in 2004. "She said, 'I'm here with a friend but I wanted to thank you. I would have have never made it if you hadn't done what you did.'"
This time, McCully's smile is a perfect fit.
