On Thursday, prosecutors charged Southall with Tate's murder.
Tate's mother, Elaynoria Martinez, said the 30-year-old Southall grew up in LeClaire Courts on the city's Southwest Side with her own children.
Southall was nicknamed "Chaos," because chaos always seemed to surround her, Martinez said. She struggled with drugs and was homeless for a while, and Martinez said her two daughters — Lakeisha and Myree — looked out for her.
"She would come over constantly," Martinez said. "They'd let her spend nights. They'd help her out, feed her, so they had a close relationship. They used to call each other sisters."
But that was years ago, Martinez said. Her daughters and Southall had fallen out of touch as they grew up.
Still, Tate's family said they were in disbelief that Southall could kill Tate, and they found it harder to believe when prosecutors said the slaying stemmed from an argument on Facebook, which may have began over a misspelled word.
According to prosecutors:
On Aug. 26 at 1 p.m., Tate went with her uncle to a nearby Citgo gas station in the 3300 block of West Harrison Street and Southall confronted her in the doorway of the gas station. The two began fighting, and Southall pulled a .22-caliber semi-automatic handgun on Tate and shot her in her leg and chest.
Southall fled to Minnesota after the shooting, and Martinez said she was told her daughter was holding Southall's ID in her hands when responders reached the scene.
The 28-year-old was pronounced dead at Stroger Hospital the next morning.
Police found Southall's ID. They also found the weapon used to kill Tate and a red dress they said Southall was wearing during the shooting at Tate's boyfriend's house, Assistant State's Attorney Joe Crocker said.
Police found Southall in Rochester, Minn., on Sept. 5, when she was arrested in an unrelated incident there.
After her arrest, Southall told authorities she and Tate "had a previous argument on Facebook and that she and the victim did not like each other," Crocker said.
According to family, Southall had written a message to Tate's older sister as well as her uncle, criticizing the two for misspelling words in message posts.
Martinez said Tate replied to Southall, telling her she was insulting her uncle over something that ultimately did not matter. That sparked a trash-talking exchange between Southall and the Tate sisters. Initially, the two took the back-and-forth as a joke, Martinez said.
"They were laughing, like 'this girl is crazy,'" she said.
The sisters ended the conversation after Southall allegedly threatened Tate, saying she planned on "burying [her] ass," Martinez said.
Family said no one heard anything from Southall for weeks, and then the shooting happened.
Martinez said she believes Southall, who prosecutors said previously has been convicted on a drug charge, may have been under the influence when she killed her daughter.
Citgo gas station employees who witnessed the shooting said they believed Southall confronted Tate about a man the two were involved with, but family members dismissed that claim as untrue.
Martinez described her daughter as a loving person who never had enemies. Tate's uncle, John, said his niece loved to help people.
"Lakeisha had the heart of, like a philanthropist," he said.
Her mother agreed, adding Tate was known as "Soul" for her warm personality.
Family said Tate styled hair for people around the neighborhood and loved to bake. Martinez said Tate's dream was to open a cafe and salon.
At her home Thursday, Martinez sat at her kitchen table and looked through pictures of her daughter the family used to create an obituary.
"It still hasn't sunk in yet," she said of her daughter's death. "It's so unbelievable. I don't understand it."
Martinez said she is glad Southall had been charged with the murder; she said she feels "justice is being served."
And Martinez said she plans to go to each court date. She said maybe then she will find out exactly what Southall was thinking when she allegedly pulled the trigger. Still, she said it is hard personally knowing her daughter's killer.
"I'd rather it have been a stranger," she said.