Claire McDonald, 35, from Inverness, died instantly after the collision at about 1.40am on the A82 Inverness to Fort William road near Abriachan in 2012.
Her partner of two-and-a-half years, 35-year-old baker, Ritchie Vaughan, was a passenger in her black Renault Clio and was seriously injured.
The driver of the other car - a silver Renault Megane - Alistair Mackintosh, 24, of Bla-Bheinn, Balnain, Drumnadrochit denies causing her death by driving carelessly and failing to keep a look-out for other vehicles and hazards on the road.
He is on trial at Inverness Sheriff Court and the jury heard from Mr Vaughan about the night his girlfriend and mother of a teenage son, was killed.
Mr Vaughan told the jury that Ms McDonald had only recently passed her test and had bought her car a month earlier.
He said the pair had gone out stargazing just before midnight and picked Loch Ness because of the lack of light pollution.
"We drove a bit along the road and she decided to do a three point turn to head back to Inverness.
"She had just finished reversing but she stalled the car.
"I can't remember if she had her lights on. Then I was aware of another car coming towards us.
"Claire tried to start the car again and the next thing I remember was paramedics treating me."
He agreed with defence lawyer Ann Bonomy that Claire was a nervous driver.
The trial continues.