A police summary of facts reveals that members of the public had reported Carter's "erratic" driving to police as she drove from Tauranga to Hamilton on State Highway 29.
Her vehicle was seen crossing the centre line which caused trucks to swerve out of the way.
A witness phoned police when she came across Carter's vehicle at the intersection of SH29 and SH1, describing her driving as "a bit wobbly on the road".
Major roadworks were being carried out between the Cambridge Golf Course and further south at the intersection of Hickey Rd as part of the Cambridge section of the Waikato Expressway, where northbound traffic had come to a stop.
Mrs Davies was sitting in her Toyota Echo which had its brakes lights on.
Meanwhile, Carter continued to weave between lanes before moving into the same lane as Mrs Davies and crashing into her car, causing it to spin out to the left for 19 metres with the rear of the vehicle coming to rest in a hedge.
Carter's vehicle stopped about 50m up the road.
Mrs Davies was taken to Waikato Hospital however she succumbed to her injuries at 2.55am on February 1.
Carter suffered minor injuries.
A sample of Carter's blood was sent to ESR for testing which tested positive for the Class A drug P and Class C drug codeine.
When interviewed by police on April 15, Carter admitted smoking P while in Tauranga and said the effects lasted between 12 and 24 hours. She had not smoked any P for a couple of days before that.
She couldn't remember the journey from Tauranga to the crash scene until immediately prior to impact but admitted causing the crash.
Carter was also not wearing her correcting lenses which she was required to wear at all times when driving.
Her vehicle was also unwarranted and unregistered.
She was convicted by Judge Heather Simpson and remanded on further bail for sentencing in February.
