Investigators say Victoria Garrick stabbed her boyfriend, 34-year-old Kevin Brooks, in the neck as he drove on I-45. Garrick's two small children were in the backseat when it happened.
Brooks was able to pull over and get out of the car. The inbound lanes of the Gulf Freeway were blocked as police responded.
The two children were taken into CPS custody.
Garrick, 21, faces aggravated assault charges.