Meanwhile, the two men accused of striking Williams and her kids - Joseph Reed, 10; Terrence Moore, 7; and Keiearra Williams, 15 - were arraigned early yesterday.
Jonathan Rosa and Cornelius Crawford were denied bail and were taken to the Curran-Fromhold Correctional Facility in Northeast Philadelphia.
At least one news report yesterday said that Rosa, 19, had been placed on suicide watch. But prison-system spokeswoman Shawn Hawes said that was not the case.
Hawes said that both Rosa and Crawford, 24, were being held in the prison's health-services wing.
Although the wing is primarily used to treat ill patients, it also can be used to house inmates involved in high-profile cases that could present security concerns, she said.
Rosa and Crawford each were charged Monday with three counts of second-degree murder, as well as robbery, aggravated assault, kidnapping and involuntary deviate sexual intercourse.
They are scheduled to face a preliminary hearing Aug. 13.
At last night's prayer service alongside a heartbreaking collection of stuffed animals and other mementos dedicated to the three young victims, city leaders commended residents for aiding in the crash investigation.
"Thank you for spreading the right name, the right information," said Deputy Mayor Everett Gillison, who praised police investigators and thanked the crowd for helping to "solve the case."
"We have to keep doing this," he said.
Authorities have said that Rosa and Crawford attacked a real-estate agent Friday morning at 6th and Cambria streets as she was returning to her Toyota 4Runner after a real-estate transaction.
The duo allegedly forced her into the vehicle and sexually assaulted her, then barreled through the area at high speed.
One of the SUV's tires blew out near Germantown and Allegheny avenues, and the vehicle plowed into a small fruit stand. Williams' children, selling fruit to raise money for their church, were struck and killed. Williams was hit and critically injured.
Williams' sister-in-law, Renee Thomas, said that she remained at Temple University Hospital last night, "fighting" for her life.
A neighbor of the family, Thelma Brown, also was injured in the crash. She was in stable condition at Hahnemann University Hospital last night and was expected to be released soon, according to Ronnie Amos, a close friend to Williams and her family.
Amos, who lives across the street from the family and knew the three children, was overcome with grief.
"If you would have met these kids, you would have seen they were the sweetest on earth," Amos said as he lit a candle at the service.
"They were quiet and respectful. . . . I'm gonna miss coming home from work and seeing them smile."
A funeral for the three victims is scheduled for 11 a.m. Monday at the North Philadelphia Seventh-day Adventist Church, on Oxford Avenue near 16th Street.
A church spokesman confirmed that NBA Hall of Famer Charles Barkley had contacted the family and will be paying for the funeral.
As arrangments were being finalized, questions were raised about the reward in the case.
A news report yesterday said that Rosa's mother had declined the $110,000 reward posted by the city and the Fraternal Order of Police Lodge No. 5 for the arrests and convictions of the suspects. But police spokesman Lt. John Stanford said she was never offered the reward.
"A number of citizens actually provided information to investigators," Stanford said. "All of that will be forwarded to the Mayor's Office, and they'll divide the reward appropriately when the case is resolved."
A fund to benefit the family of the children has been set up at Education Works, a nonprofit group based at Germantown and Allegheny avenues.
Donors may contact Kim Alexander, the group's human-relations director, at 215-221-6937. Donations also can be dropped off at the center between 6 a.m. and 6 p.m., or mailed to Education Works, 3149 Germantown Ave., Philadelphia, Pa., 19133.
On Twitter: @dgambacorta