The billboards with a photo of Khamaya Donelson include the FBI's $25,000 reward for information leading to the killer's arrest and conviction.
Editor's note: The video above originally aired on July 26.
Crime Stoppers Houston is offering an additional $25,000 thanks to a donation from Houston Rockets owner Tilman Fertitta.
Her mom was stopped at a stop sign in the Greenspoint area when shots were fired from a silver 4-door 1999 Honda Accord that was speeding by. One bullet entered Watters' vehicle, striking Khamaya in the face and also hitting Khamani.
Watters said her daughter died in the car before she could get her to the hospital.
Anyone with information is urged to call FBI Houston at 713-693-5000. You can also call the Houston Police Department Homicide Division at 713-308-3600 or Crime Stoppers anonymously at 713-222-8477.
Details on the shooting
Watters had just closed up the restaurant she was working at and left to go get her two kids that were at a 24-hour daycare center, police said.
As a treat, she took her kids to get some ice cream.
On their way home just before 1 a.m., the family was stopped at Northborough Drive and Rushcreek Drive, police said. The gunman was in the Honda with three other males and heading west on Rushcreek, according to HPD. He fired from the rear driver's side into the family's vehicle.
Detectives believe they were involved in a shootout with someone at a nearby food store and Khayama was caught in the crossfire.