A woman who raped and then bombarded a teenage girl with text messages sat in the prison dock and asked for her phone back moments before being sentenced.

Tammy Lee Humphrey, 23, of Blackburn, had used the very same phone to torment her young victim after luring her to a park in Chadstone, in Melbourne's southeast, and raping her.

The predator had already been forbidden by a court from contacting the vulnerable 15-year old amid concerns by welfare workers that she had an unhealthy interest in the girl.

They were right.

Tammy Lee Humphrey, 23, spent four months in jail after failing to leave her victim alone

Humphrey was sentenced in the County Court of Victoria to an 18-month Community Corrections Order, with a condition she be supervised while free in the community.

She had already spent four months in jail over the disturbing crime.

Humphrey pleaded guilty to a charge of sexually penetrating a girl under 16 and multiple charges of stalking and breaching intervention orders against different women.

She was free in the community on a good behaviour bond over another stalking incident when she molested her victim.

Humphrey's defence had tried to get her off the hook by arguing she was not fit to stand trial because her intelligence was so low that she could not understand what was going on.

A jury disagreed and Humphrey agreed to plead guilty and avoid the trial altogether.

The court heard that Humphrey's young victim was lured out on October 4 last year on the promise of free booze.

Once alone, Humphrey raped the girl, who although showed 'mutual interest', is unable to legally provide consent.

Humphrey was arrested and charged days later, but released on bail on the provision she not go anywhere near the victim.

She didn't listen and over the next few months bombarded the teenager with bizarre text messages.

In one message, Humphrey tried to convince the teen to meet her because she was afraid of a storm.

'The storm's around. I need you ... there's lightening around. We both know we hate thunderstorms,' she wrote.

Tammy Lee Humphrey, 23, mercilessly tormented her young victim even after raping her

Tammy Lee Humphrey appeared worried about the fate of her phone before her sentence

She even met up with the teen again and bought her more booze.

The teenager repeatedly asked her stalker to leave her alone, telling her to 'f**k off now please'.

Judge Mark Taft said although Humphrey carried on with a 'child-like quality' she was also extremely manipulative.

He said Humphrey had harassed another woman while free on bail, tormenting her with texts and calls and meddling with her life.

'I know you hate my guts but I'm very sorry for all your friends I took away from you,' Humphrey wrote in one text.

The deranged stalker was eventually taken off the streets in July after repeatedly breaching her bail conditions.

Her victims refused to submit impact statements to the court.

Judge Taft said Humphrey had led a troubled life from birth due to being born to a heroin addict.

She was placed in foster care and suffered from a mild intellectual disability, depression, anxiety and obsessive compulsive disorder.

He took all that into account when sentencing her to an 18-month Community Corrections Order.

Humphrey is expected to take up residence with four men, under supervision, and will be restricted to the use of just a landline phone and banned from social media.

She will also have to adhere to a strict night-time curfew and only mingle with the community while in the presence of a care worker.

She was placed on the sex registry for the next 15 years.

Judge Taft ordered her mobile phone be destroyed.