Investigators said on Tuesday, a couple was driving along West Road near Barker Cypress when they pulled into a parking lot during an argument.
The woman was injured after she jumped out of the moving vehicle while her boyfriend was driving, according to deputies.
Authorities said a witness stayed with her until first responders arrived.
Detectives told ABC13 that the woman was flown to the hospital, where she died.
During an early investigation, authorities told Eyewitness News they detained her boyfriend for questioning, and in an update, they said he is not charged.
Editor's note: Deputies with the Harris County Sheriff's Office said they responded to a call about a person jumping out of a car. Initial reports show they were investigating whether she was pushed or voluntarily exited the vehicle.