Simon Stirling, defending, suggested Mitchell’s actions were a result of “inexperience rather than irresponsibility”.
He added that Mitchell had only passed her driving test three weeks earlier and would not have understood the risk of the manoeuvre she was attempting.
Gloucestershire Police said an analysis of Mitchell’s social media found that she had been filming Snapchat videos while behind the wheel.
These videos showed her “lack of care for driving safely”, police said, with one showing her veering onto the opposite side of the road towards an oncoming car as friends shouted for her to stop.
Judge Lowe said: “You were, at the time, a reckless and immature young driver suffering from the frankly common teenage delusion that you were invulnerable and free to do as you wished.
“The lives of all the victims and their families have been irrevocably changed.”
Mitchell must serve half of her sentence in custody before being eligible for release on licence.
She has also been disqualified from driving for eight years and four months, must undertake an extended driving test to regain her licence, and was ordered to pay a statutory surcharge.