But no one came to her aid, despite one of the two sisters who allegedly pimped her being in the next room.

The sisters allegedly preyed on the homeless girls and introduced some of them to illegal drugs before prostituting them to middle-aged men.

The ring in south-west Sydney operated for three years and included a girl as young as 12, who was sold for sex three times in three days, the court was told.

Accused ringleaders Adrienne Garner, 22, and Tahlia Garner, 19, of the Liverpool area, and four alleged customers, aged in their 50s, appeared in court yesterday.

Police charged them with a total of 50 sexual assault, child sex and child prostitution offences dating back to November 2008.

Adrienne Garner's three young children were on the premises on at least one occasion when one of the men had sex with a girl, police allege.

Both of the sisters and alleged customer Elia Toma, 55, applied for bail, which Campbelltown Local Court magistrate Robert Rabbidge refused.

The other alleged customers - Bassam Darwich, 52, Trevor Weger, 51, and Rino Mura, 53 - did not apply for bail, which was formally refused.

``Sue'' was 13 and a virgin when she was living with the Garners and was twice sexually assaulted by Mr Weger, it is alleged.

When she objected to Tahlia Garner's order to work as a prostitute if she wanted to continue living with them, she was told ``Just do it . . . You're going to do it in life anyway''.

Police allege that Mr Weger sexually assaulted Sue in a bedroom as her cries went unanswered.

The Garners' solicitor, Michael Blair, told the court that some of the victims were known ice users and all must have been complicit in the alleged prostitution if they continued to associate with his clients.