A teenager who disguised herself as a boy to date her own female friends, some of whom were underage, was jailed for 30 months on Monday.

Gemma Barker, 20, admitted fraud and sexual assault after she turned herself into a series of different boys and seduced her friends. Barker, who was 19 at the time, even created separate Facebook accounts for each identity, Guildford Crown Court heard.

According to Chetna Patel, defending, the teen changed her identity to "become the boy" her friends wanted.

During the hearing, Patel referred to probation and psychological reports which found she suffers from autism spectrum disorder and attention deficit hyperactivity disorder, commonly known as ADHD.

"Miss Barker struggles to understand the motives and the intentions of others," she said, telling the court that her client wanted to become "the perfect boy" for each of the victims.

Barker had committed repeated sexual assaults - up to 20 on one girl, by pretending to be a boy, and possibly half that number on the other girl, using two more male disguises.

Her 15 and 16-year-old friends were fooled by Barker's deception and started relationships with her, which involved "kissing, cuddling and groping".

When one of Barker's victims became suspicious, she reported the defendant to the police who eventually discovered the truth. Whilst being investigated, Barker even claimed to have been assaulted by one of her fictional characters, "Luke Jones".

Barker, of Staines, Middlesex, was told by Judge Peter Moss at the court that she would be in custody for the first half of the term and serve the remainder on licence.

He said: "I have concluded that these offences are so serious that only a custodial sentence is appropriate."

Moss then told Barker: "Nothing that you have ever said to any expert or the police sheds any light on, or provides any understanding of, your motivation for these offences.

"Nor have I nor anyone else seen any flicker of remorse for what you have done."

The judge added Barker's guilty pleas were "a complete reversal of the position you had held up until then", having previously used "persistent lies and denials".

Barker showed no emotion as she left the dock to start her sentence, to be served at least initially in a young offenders' institution.

She had previously admitted two counts of sexual assault and one of fraud. The offences took place between November 23 2009 and May 10 2010.