A young woman convicted of conspiring to beat up and rob a disabled Mount Pearl man has been sentenced to nine months in open custody and time served.

There is a court-ordered ban on her name because she was 17 when the crimes occurred, which classified her as a young offender.

She was one of five people arrested after the disabled man, who is in his early 20s, was lured outside and robbed near Mount Pearl Square in September 2012.

Assault detailed in text messages

Text messages she sent before the attack provided details of the plan.

After the assault, she sent a text message saying: "I broke his nose and split open his face. Ha, ha ... I f**ked him up."

Time served, open custody

The young woman had been in custody for 109 days at the youth correctional centre in Whitbourne since her arrest.

In addition to the time she has served, she was sentenced to nine months in open custody, which means she won't be locked up but she will be monitored closely.

When Judge Pamela Goulding read the sentence, the young woman turned to her mother, smiled and said, "open custody."

'Inadequate sentence'

Michelle Murdoch, president and chairperson of the Coalition of Persons with Disabilities, said she fears the young woman's sentence is inadequate.

Advocate Michelle Murdoch is disappointed with the sentence. (CBC)

"No amount of sentencing is going to change the experience for the young man that was assaulted," said Murdoch. "So in regards to that, nothing will change that. I'm not so certain the sentence is one that is going to say 'don't do it again.' "

The four other people charged after the attack are due in court later this year.