Emma Czornobaj has pleaded not guilty to two counts each of criminal negligence causing death and dangerous driving causing the deaths of Andre Roy, 50, and his 16-year-old daughter, Jessie.
Witnesses have said the accused was tending to a family of ducks when the accident occurred on a westbound lane of Highway 30 near Candiac, a suburb south of Montreal.
A Quebec provincial police officer tasked with reconstructing the scene of the accident in June 2010 told the accused's jury trial that Czornobaj's vehicle was parked in the left lane of a busy highway south of Montreal but that she wasn't in it.
"The collision was caused by a human factor," said Samuel Beaudet. "The driver of the Honda (Czornobaj) parked in the left lane on a limited access road and got out of her car.
"The driver of the Harley-Davidson (Roy) was surprised by the presence of the Honda in the left lane and was not able to come to a complete stop or take evasive action to avoid a collision."
Beaudet, the final Crown witness, said Roy was going between 113 and 129 km/h at the moment he applied his brakes. Beaudet said Roy managed to slow down to between 105 and 121 km/h at the time of impact.
Roy and his daughter, who was riding on the back seat, were propelled from the motorbike. The girl was caught under the car, which itself was launched nearly 20 metres on impact.
Roy's wife, Pauline Volikakis, was on another motorcycle behind the victims, but was able to stop and avoid serious injury.
The rear window of the accused's car was shattered and Jessie Roy's helmet and sunglasses were found in the back seat of the vehicle. It was one of several dozen images Beaudet presented to the jury of 10 men and two women.
The investigator said the crash occurred on a section of highway where the maximum speed dropped to 90 km/h from 100 km/h.
Earlier on Monday, Beaudet said both victims were wearing helmets that did not meet safety standards. Later, he specified that a visual examination of the helmets suggested they did meet standards,.
Beaudet said the helmet issue did not contribute to their deaths.
Charges against Czornobaj, who is now 25, were laid more than a year after the deaths. While the maximum sentences are unlikely, criminal negligence causing death carries a maximum term of life imprisonment, while the charge of dangerous driving causing death comes with a maximum of 14 years in jail.
The defence is expected to begin its case once the final Crown witness wraps up on Tuesday.