He had been shot to death seven days earlier, shortly after school let out at South Philadelphia High.
Yancey bowed her head and said a silent prayer: "God, take his soul to heaven."
It was Yancey's second casket of the day - and it was only 10 a.m. She had just started what would become the most grueling week she has faced since taking her unusual job.
As the district's liaison to families whose children die or are seriously injured, Yancey visits homes and hospitals, goes to funerals, and reads warm remembrances about the deceased. She helps the grieving, however she is needed.
Before the week is out, Yancey will have attended six funerals in six days - twice as many as her previous high.
She will have looked into the faces of six dead boys. Four had been slain - none of them on school grounds. They were victims of an increasingly violent city where 31 children under 17 were killed this year. Of the other boys she would mourn during the week, one had died after surgery. The other, who suffered from asthma, had died in his sleep.
The week would test her abilities: She would fight back tears when yet another grief-stricken mother looked into her eyes for strength. She would negotiate into the night for money to help a family bury a son. She would rue having made a sensitive mistake at one funeral, though no one could blame her.
"Six deaths of six students - it's not normal. It's not right," Yancey said Friday. "You don't expect children to die."
Monday
Dressed neatly with her waist-length hair pulled back in a ponytail, Yancey arrived about 9 a.m. at Deliverance Evangelistic Church in North Philadelphia.
The church was about to host the funeral of 13-year-old Jevon Chestnut, who was shot in the head in his home, allegedly by a friend. A police officer asked Yancey, what brought her to the service.
"I'm here for the families," she said.