NRL star Hynes' letter helps free his mum from jail

She must live in his granny flat in Cronulla for at least two years, although he'd told the court he was happy for it to be forever.

"The fact that her sons are beside her providing her this support reflects on her as a parent," NSW District Court Judge David Wilson said on Tuesday.

"She has done an excellent job raising her two sons which will now provide her with the same support she has provided them all their lives."

Hynes had been behind bars since February when she was found guilty of heroin supply after a close family friend was found dead in her living room.

Judge Wilson said letters written by her sons were key to a reduced sentence.

"Most persuasive were the carefully worded and considered testimonials by her two sons," he said.

During sentencing, the court was told of Hynes' "depraved" childhood, consisting of abuse, violence and a distrust of authority figures.

The embattled mother's life took a turn for the worse when her partner died in a car accident and she began using ice and speed to cope.

"I don't think I'll ever come to terms with his death," she told a psychologist.

Judge Wilson said her release into the care of her sons was a new chapter, but warned her to obey her conditions or she could land back in custody.

Hynes will have to live with Nicho for two years, and submit to regular random drug and alcohol testing.

She will also need to complete 240 hours of community service as well as attend rehabilitation programs.

The weight of responsibility now sits on the halfback's shoulders, as he is tasked with steering his mother away from drugs all while steering the Cronulla Sharks towards a premiership.

"We're really proud to stand here side by side now and go home and look after mum," Nicho Hynes said outside court.

His mother emerged from Downing Centre District Court in fresh clothes with both sons hanging off her arm.

"Nicho will continue to do great work with the support of his brother and father," she said.