Chloe Goodman was 17 when she posed with the replica Mac 10 in what looks like a school locker room as a friend stands back-to-back with her brandishing a similar firearm.
In a second photo Goodman poses with a gun in a lavatory and in a third holds a toy gun as she plays an arcade game.
A court heard how Goodman thought it would be 'cool' to hang out with hoodlums but the pictures were found on her Facebook page when she was arrested for taking £300 to hide a loaded gun for a thug from a vicious crime gang.
Today Goodman, now 18, sobbed as she began three years in jail after the impressionable youngster was said to have got a 'buzz' out of associating with gangsters.
At Minshull Street Crown Court, Manchester, Goodman, wept as she appeared with another girl of 17 and two cousins from the South Manchester-based Lostock Crew, which has brought misery to the suburbs of Flixton and Urmston.
She was given a mandatory three years for illegal possession of a firearm and ammunition after claims she 'embraced' gang culture.
Judge Timothy Mort told Goodman: 'A gun is used to reinforce a culture of territory or drugs and therefore it has no place in our society.
'That is why Parliament brought in mandatory sentences. The reason for that is because everybody is so concerned about the availability of guns in the community.
'From access to your computer it is clear that at the time you saw it was cool to be associated with lads who were on the fringes of gun culture in the area.
'Various images show that it was something that gave you a buzz.
'And it does seem to me that when you were asked to take this gun you were not that reluctant because it was seen as cool.
'I am satisfied that there was no intention to use that gun. You probably didn't give much thought to the fact that it was intended to shoot people.
'Although you clearly know lads on the fringes of that.'
Earlier the court heard how Goodman, from Urmston, had been friends with gangster Daniel Brown, 21, and regularly communicated on MySpace with a senior thug in the Lostock Crew.
Brown had served jail terms for robbery and drug dealing and was renowned for racketeering and demanding protection money from locals.
In May last year Brown drew up outside Goodman's house in a car with four friends and handed her a Smith and Wesson double action 0.44 revolver containing five bullets and wrapped in a white sock.
Mr Ian Metcalfe prosecuting said Goodman took the gun and told the younger girl she was 'looking after some heat for Danny B'.
She said Brown had told her it could 'blow her head off if she handled it' and described her situation as a 'load of pressure'.
But just hours later police raided Goodman's house following a tip off and the gun was stuffed in the 17-year-old's handbag and tossed out of a back window and landed on a hedge.
Officers found Goodman in the living room making calls on her mobile phone and the 17-year-old girl was found hiding in a storage area over a loft space.Inquiries revealed how in the run up the arrests Goodman had sent a text message to Brown saying: 'Hiya Danny, Make sure you shout us whenever you need a favour. Hold it safe yeh.'
And three days before the gun was handed to Goodman she sent a text to Brown saying 'I'm gonna watch Shameless, but ru going to bring it me tomorrow?'
Brown replied saying 'I can bring it.'
The court heard that Goodman's computer was also examined and police found pictures of Goodman 'in a series of poses which seemed to corroborate gun or gang culture' going back to 2008 which 'embraced' gun culture.
She was also found to have a photo labelled 'Lostock Boys' which shows a group of youths holding weapons.
In mitigation, Goodman's counsel Miss Sarah Johnston said: 'The photograph of the Lostock boys was not taken by her but was posted on her Facebook.
'She has suffered panic attacks during her period in custody.'
Brown, from Stretford, was jailed for five years for possessing a firearm with ammunition and unrelated offences of conspiracy to blackmail.
His cousin, Michael Brown, 22, from Davyhulme got 16 months after the cousins threatened a man who owed them money.
The 17-year-old girl, who cannot be named for legal reasons, pleaded guilty to possessing a prohibited weapon and possessing ammunition and was jailed for two years.
Det Chief Insp Chris Packer, of Greater Manchester Police said after the case: 'This case highlights the very real dangers young women face when they are persuaded by either their boyfriends or male friends to store guns.
'These sorts of criminals coerce young and impressionable girls, asking them to stash weapons and take the heat off them.
'In many cases they probably have little or no regard for these women, but simply use them to hide weapons or drugs and try and stay under the police radar.
'However, as this case has proved, hiding a gun is tantamount to hiding a crime and as these young women can now testify, the consequence of that is a stint behind bars.
'It is important to stress that some women find themselves caught up in this cycle and are pressured into hiding the guns, to the extent where they are physically threatened if they do not do as their boyfriend's ask.
'I would urge anyone who is in this position to think carefully - is it worth getting a criminal record for this man? Do not let these men ruin your life.
