A woman thought to be a passenger in a sport utility vehicle that plowed into a car on state Route 76, killing four people, pleaded not guilty Friday to gross vehicular manslaughter charges for driving into oncoming traffic.Deanna Fridley, 23, was ordered held in lieu of $3 million bail during her arraignment at the Palomar Medical Center, where she is recovering from serious injuries.Anthony Boles, 24, was originally thought to be the driver who crossed into the opposite lanes of traffic and struck a sedan Dec. 14, setting both vehicles afire and flipping them onto their roofs.Boles, an ex-convict, was charged only with possession of methamphetamine, which he allegedly had in his sock when he was arrested.Boles' driver's license was suspended four days before the crash because he didn't have insurance, according to published reports.Boles has prior convictions for driving under the influence, assault with a deadly weapon and drug possession.On Friday, Sgt. Tom Greenstone of the California Highway Patrol told reporters that witness statements at a "horrendous" and confusing crash scene led them to Boles, but follow-up interviews, Fridley's injuries and a "very clear" surveillance tape from the Pala Casino showing her getting behind the wheel of the sport utility vehicle led them to her.Besides four counts of gross vehicular manslaughter while intoxicated, Fridley was charged with two counts of driving under the influence and a misdemeanor count of driving on a suspended license.Deputy District Attorney Brenda Daly said Fridley was under the influence of both alcohol and methamphetamine at the time of the crash."She was basically driving erratically and fast and hit a guardrail," Daly said.After hitting the rail, Fridley drove into oncoming traffic and collided with the victims' car, Daly said.More serious charges, including possible murder charges, could be filed and the investigation is continuing, Daly said.Three occupants of the sedan -- Escondido residents Jesus DeSantiago, 45; his wife, Lina, 46; and Rubi Baez, 46, of Vista -- died at the scene. Baez's husband, Luis, 51, was flown to a hospital, where he died of his injuries.One of Fridley's two defense attorneys, Chet Potter, said his client was not driving the sport utility vehicle and said the $3 million bail was "excessive."Judge Richard Mills scheduled a readiness conference for Feb. 19 and a preliminary hearing for April 8.