A woman who authorities said had sex with high school boys so she could be a "cool mom" was injured while riding in an SUV that veered off an interstate a day before she was to be sentenced. The driver was a 14-year-old girl.

Sentencing for 41-year-old Silvia Johnson (search), who pleaded guilty to two counts of misdemeanor sexual assault and nine felony counts of contributing to the delinquency of a minor, was postponed. A review hearing was set for Oct. 6. She could be sentenced to 58 years in prison.

The Arvada (search) woman held parties for teen-age boys almost weekly between October 2003 and October 2004, according to investigators. They said she gave drugs and alcohol to eight boys and had sex with five. Johnson told police she wanted to be known as a "cool mom," authorities said.

On Sunday, Johnson was in an 2000 Jeep Liberty that rolled over after the teen drove off Interstate 25 and down an embankment, Colorado State Patrol Trooper Eric Wynn said.

Johnson and three other passengers — her 14-year-old daughter, 11-year-old son and a 12-year-old boy — were hospitalized with serious injuries, authorities said. Only the driver was wearing a seat belt and escaped serious injury, authorities said.

The crash was under investigation; no charges have been filed, Wynn said.

Prosecutor Lori Toll said Johnson could be charged with allowing an underage driver to take the wheel. She also said Johnson was violating a restraining order barring her from having contact with her children.

Johnson's attorney, Phil Cherner, said: "My client has gone through a great tragedy ... It's a sad day for everyone on both sides of the case."

Jefferson County District Attorney Scott Storey (search) said he was "very surprised and shocked" that a 14-year-old may have been driving while Johnson was in the vehicle. "That's very upsetting to me, especially considering what her history has been in this case," he said.