Miracle, who was born three months premature, remains in the hospital, Holmes told The Washington Post, and investigators have yet to find her mother's killer or learn what prompted the killings.
The shooting happened shortly after 6 p.m. on South Marquette Avenue, just outside Beard's family home. The victims were inside a white car when another vehicle drove up beside them. A man with dreadlocks fired several shots into the car and fled, police said. The two were taken to Northwestern Memorial Hospital, where they later died.
The man in the car with Beard was a documented gang member, according to Chicago police. Holmes said the family thinks he may have been the killer's target.
It's unclear how the victims knew each other or what their relationship was. Chicago police declined to name them, but Beard's family has since spoken publicly about her death.
Holmes said there were surveillance cameras in the neighborhood, but police declined to provide more details about the investigation.
Beard and the unidentified man are the latest in a growing number of casualties in Chicago this year.
According to data compiled by the Chicago Tribune, 3,122 people have been shot since January in a city with a population of roughly 2.7 million. That number had surpassed last year's total by more than 100.
Of the people shot this year, 530 were killed, according to the Tribune's data, compared to 491 last year.
Chicago also has logged more homicides since January than New York City, which has more than three times the population. As of September 11, New York City has had 242 homicides, according to the police department. That's less than half of Chicago's death toll for the year so far.
According to the Chicago Police Department's crime map, nearly 200 people in the city were killed in the past three months alone. To put that into perspective, that number is just a little less than New York City's total since January.
A new report by the Brennan Center for Justice found that half of the increase in crime this year nationwide is because of the spike in Chicago.
Beard, who worked at a restaurant, also had a 4-year-old child, Holmes said.
"She was excited about being a mother," Holmes said. "She was looking forward to giving birth to this child."
A relative of Beard's did not return a call from The Post on Tuesday morning.
Sylvia Jones-King, Beard's grandmother, told a Fox affiliate that Miracle is breathing on her own.
"A lot is going through my mind. I have to be strong," Beard's mother, Crystal Jones, told a CBS affiliate. "I just want justice. That's all I ask, is that I have peace, that's it."
