Jazmine Barnes was shot and killed on Sunday near a Walmart along the east Beltway and Wallisville Road.
She was inside her family's vehicle with her mother and siblings.
Jazmine's mother, 30-year-old LaPorsha Washington, said she was taking her daughters to the store to get coffee, when investigators say someone in a red, 4-door pickup truck pulled alongside them and fired.
Jazmine died at the scene. Her mother was hospitalized with injuries, but was released on Tuesday night.
She and Jazmine's siblings had planned to go to the sheriff's office Wednesday morning to talk to a sketch artist, so they could make a sketch of the suspect.
However, Jazmine's 15-year-old sister, who was in the front passenger seat, started complaining of neck pain. She went to the hospital after glass was discovered still in her neck.
Their 6-year-old sister is also now at the hospital after finding glass in her leg.
"I'm just here. When I say, 'I'm just here', I'm taking it one day at a time and I'm here. I got three other kids that need me to be strong for them and they're going through a lot," Washington said.
The shooter is described as a white man in his 40s, with a beard. He was wearing a red hooded sweatshirt and driving a red pickup. His motive is unknown.
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Some activists say a similar, unprovoked incident happened to a man named A'Vonta Williams a little more than a year ago.
Williams was reportedly shot multiple times by a white man in a pickup truck while driving near that same Walmart on Wallisville. Williams recovered from his injuries.
Activists say they don't believe the two shootings are a coincidence, and that's why they're concerned about Jazmine's case.
The activists spoke outside of the sheriff's office Wednesday morning, calling on the community to take action in finding the shooter in Sunday's incident.
The Harris County Sheriff's Office responded, explaining the weapon, vehicle and suspect description from Williams' case did not match Jazmine's shooter. The 2017 shooting suspect's truck was described as a white or gray/silver Ford pickup, which is a different color from the Barnes' case. They say there was no mention of facial hair in the suspect's description from 2017, and a different weapon was used.
The sheriff's office says they did an exhaustive search for the suspect.
Activists plan to hold a Justice for Jazmine community rally in the Walmart parking lot on Saturday at noon.
"I want to make sure that love wins. That when we show up Saturday... that all Houstonians with a heart of compassion who desire justice will show up on Saturday, so Houston can be looked upon as a place where all Houstonians, all Americans can feel safe and comfortable," said Pastor E.A. Deckard.
Journalist Shaun King and civil rights attorney Lee Merritt have come together to offer a $50,000 reward for Jazmine's killer.
"I'm loving that the community is getting together, and everybody is raising money and a reward has been put out," Washington said.
If you have any information about the shooting, call the Harris County Sheriff's Office or Crime Stoppers at 713-222-TIPS.
You can also make an anonymous tip online at www.Crime-Stoppers.org.
SEE ALSO: Search for clues after 7-year-old shot while leaving Walmart with her mother