Raleigh police and relatives of Cobb confirm she was killed at her apartment on Sardis Drive late Friday night.
Williams, 33, was detained at the scene, and eventually charged with murder.
"They caught her there," Cobb's niece Angela Calloway said. "From my understanding they caught her there. What was she doing there? Why was she even in her house?"
Relatives say the suspect moved into Cobb's apartment complex at Carolina Terrace on Sardis Drive in Southeast Raleigh a few weeks ago, but a motive for the assault remains unclear.
"It's just hard right now for the whole family because we're a big, big family and we love each other to death. And it's just wrong, it's just wrong and it's sad," Cobb's niece Tanikia Jones said.
A family member tells ABC11 Eyewitness News that Cobb had called to alert them Friday that she was headed to hospital after her husband complained of chest pains. Cobb reportedly followed the ambulance. She'd promised to call when she returned home, but never did.
On Monday, Williams had to be restrained and wheeled into the courtroom after refusing to enter. She yelled obscenities and said she did not comment the crime as a judge read the charges against her.
After the court hearing, Cobb's family gathered to mark what would've been her 47th birthday.
They say she worked second shift as a cab company dispatcher, she loved to cook for everyone and play with the neighborhood kids since she didn't have her own. Cobb also worked as a part-time elder care nurse, according to relatives.
"They took a very special person away from us," Jones said. "They took a very special person away from us. We can never forget her because she was good to everybody."
For now, Williams will remain behind bars without bond.