The home detention sentence given to fatal hit-and-run driver Rouxle Le Roux will not be appealed by Crown Law.

The 19-year-old was sentenced last Friday to 11 months' home detention over the death of 15-year-old Nathan Kraatskow in May at an Albany intersection.

It was revealed Le Roux, a learner driver, had consumed wine and cannabis earlier that day and took 16 hours to report the incident to police. She also came under fire for making light of the situation in several Instagram posts.

"Only thing I'll be catching," she wrote with the hashtag "Canthurtemifigotnone" - apparently referring to no longer being allowed to drive.

Her sentence sparked a public outcry, with many calling for Le Roux's sentence to be appealed. Almost 160,000 people have signed a petition to give her a stronger sentence.

But Crown Law has now confirmed to Newshub there will be no appeal.

"The Deputy Solicitor-General (Criminal) has reviewed this matter, as well as two other counsel within Crown Law. The matter has been treated with urgency, in order to give the victim's family an answer before the Christmas break," Crown Law wrote in a statement.

"We consider the sentence imposed on Ms Le Roux was appropriate in all of the circumstances of the case, and there is therefore no basis for an appeal. The Police advised the victim's family of the decision this morning."

National said after sentencing the case shows New Zealand needs to be tougher on crime, but a prominent lawyer has warned against letting social media backlash dictate policy.

"A lot of people who have gone on social media - with respect to them all - they will not know what the judge knew," Marie Dyhrberg QC told RadioLIVE.

"To put a young person in prison, you may say is not going to help her be rehabilitated, to take responsibility for what she has done. Home detention is actually a tough sentence."

Newshub.