Rebecca Hannibal, the NSW teenager who supplied ecstasy pills that killed her best friend Georgina Bartter at a Sydney dance party, has been sentenced to a 12-month good behaviour bond.

Georgina Bartter, 19, collapsed at the Harbourlife festival last November and later died in St Vincent's Hospital from multiple organ failure.

Hannibal pleaded guilty in the April this year to supplying Ms Bartter with the party drug.

The pair had purchased the drugs from a supplier through Hannibal the day prior to the music festival.

On the afternoon of the event, Ms Bartter took one and a half pills but within a few hours suffered the adverse reaction.

In making the finding, judge Graeme Henson said the girls in the "full flower of youth" were exploring the world of drug taking with no understanding of what could go wrong.

Judge Henson said they were well aware of the consequences and had taken ecstasy before.

"Two young women, close friends, go to a music festival, they make a foolish decision, only one comes home," Judge Henson said.

Georgina Bartter, 19, collapsed at the Harbourlife festival last November and later died from multiple organ failure ( Supplied: Facebook )

But he pointed some blame at those selling drugs.

"The real evil in this case is not present in this room," he said.

After the judge handed down the finding, Hannibal cried and hugged her parents, who had sat with her throughout the hearing.

Matthew Forti, who sold the ecstacy tablets to Hannibal, pleased guilty to supplying the drug MDMA in May and is due to be sentenced later this year.

Judge Henson said of drug dealers: "They close their minds to the reality they may be selling a death sentence."

The court heard Hannibal now suffers from depression, anxiety and is at risk of developing post traumatic stress disorder.