A paramedic who crashed an ambulance into another car on the Pacific Highway near Valla last year, killing two people, admitted she took cannabis the night before the fatal crash.

Gaye McKay, 57, ate a cannabis cookie before she drove the ambulance involved in the fatal crash at around 5pm on November 20 last year.

The crash killed 50-year-old Dixie Erlandsen, a club president for Urunga Football Club, and her 17-year-old daughter Rachel, who were travelling in the other car. Another paramedic, a doctor and a nurse who were in the ambulance at the time desperately tried to revive the pair.

Blood samples taken from McKay after the crash revealed a small amount of cannabis in her system, a level experts say shouldn’t have impaired her judgement.

Ms Erlandsen’s mother Mavis Erlandsen told 9NEWS it was no excuse for McKay’s errant behaviour.

“They’re dealing with people’s lives and they’re out there driving ambulances at high speed,” she said.

The Coroner found McKay was not responsible for causing the crash. It is believed the car pulled out in front of the ambulance while they were responding to an emergency at high speed.

“I just think there should be a test that they are clear of any alcohol or drugs or anything before they go to rescue someone else,” Ms Erlandsen said.