An 72-year-old woman who killed a motorcyclist when she drove on the wrong side of a motorway in Wellington has been sentenced to six months community detention.

Photo: RNZ / Richard Tindiller

Kathleen Grey was sentenced in the Wellington District Court today.

She previously pleaded guilty to the charge of aggravated careless driving causing injury or death.

A 25-year-old man, Samuel Trent Jackson-Seligman-Lemaire, died when Ms Grey's car collided with his motorcycle on State Highway 1 near Johnsonville in December.

Whānau and friends of Samuel filled the courtroom, and through victim impact statements talked about a man who was loved and cherished by many, and was due to be married two months after he died.

His mother said Sam was a big-hearted, legend of a man, who was dearly missed.

"To live life without our Sam is going to be so hard to do."

She said if she lived to 80 she would have nearly 30 years to live without her "darling boy".

But he was a forgiving person, she said, and she forgave Grey for taking his life.

"I know that," she said, "I just want to say peace be with you."

In a statement read by victim support his fiancée said some nights she couldn't sleep, and when she did, she had nightmares.

She said now her daughter's father was missing out on seeing her grow up, and start going to kindy.

She said her daughter was now bonding with her father through his box of ashes, talking to it.

After the court hearing family told media they were not happy with the sentence, saying while they did not want Grey sentenced harshly, they felt six months community detention was not fair.