A teenager killed her best friend when her car hit a tree while she was 'showing off' by 'driving unacceptably fast'.
A court heard that Naomi Jones had hit two significant bumps in quick succession, but did not slow down and then lost control on a blind bend.
The car crashed, leaving her passenger Elysia Ashworth, 17, with fatal injuries.
Now Jones, 19, from Wesham, Lancs, has been convicted of careless driving, although she was cleared of causing death by dangerous driving.
At Preston Crown Court, she was sent to a young offenders' institution for six months.
The Judge, Christopher Cornwall, said the verdict should not be called into question but, in his judgment, it was not far short of dangerous driving.
Jones admitted to the court she failed to negotiate the left-hand bend on the narrow, uneven Division Road, Blackpool, in July last year.
An accident investigator later examined the scene and estimated the speed at point of impact with the tree at between 30mph and 35mph.
It could not be determined what her approach speed was but it must have been greater than 35mph, the jury was told.
Judge Cornwall told Jones: "There seems to have been every conceivable reason that you should have reduced your speed on that road.
"There is no doubt in my mind that the considerable jolt you experienced ought to have acted as a warning that your speed was unacceptably fast.
"There was no evidence of braking only a desperate attempt to steer around the corner which failed."
He accepted she was not racing but pointed out 'there may however have been an element of showing off to your friends in the car and those following'.
He added she was 'driving at a wholly unacceptable speed'.
A second passenger, Ellen Richardson, suffered two fractured vertebrae in the crash.