A woman prisoner in Hydebank Offenders Centre has asked the Human Rights Commission to inspect the conditions in which she is being held.
The women have now been moved to a facility in Belfast
She claims she is locked up 23 hours a day and forced to wear an anti-suicide suit.
The Prison Service recently transferred women from Maghaberry Jail to Hydebank where it says it could provide a better environment for them.
However, the 18-year-old woman and her solicitor say conditions have not improved.
Last month, the treatment of woman prisoners in Northern Ireland came under fierce criticism from the commission.
It said it had uncovered human rights abuses at Mourne House in Maghaberry where the regime was studied between March and June.
It talked of a woman dying in her cell, two suicide attempts and a girl held in isolation in a cell with no mattress and a potty for a toilet.
However, the Prison Service said conditions at the new facility in Belfast, to which the women have now been moved, offered better conditions for inmates.