Serious concerns have been raised about why a girl, who is alleged to have been sexually abused by more than 12 people before being taken into care at the age of ten, was not taken into care earlier.

The girl who was alleged to have been subjected to "devastating" sexual abuse in her home, has been made a ward of court.

High Court President Mr Justice Peter Kelly said the case raised serious issues.

Her court-appointed guardian raised concerns about why the girl and her siblings were not taken into care earlier, as social work services were familiar with the family before the girl was born.

The girl was eventually taken into care in 2010, aged ten. She is now 18.

Professionals involved in the girl's care told the High Court she was an incredibly vulnerable person who could be at risk sexually, socially and financially if she were to look after her own affairs.

Psychiatric reports were presented to the court showing she lacked the necessary capacity to manage her affairs and finances.

Mr Justice Kelly made her a ward of court and appointed the general solicitor for wards of court, Patricia Hickey, to represent her interests and vindicate her rights.

He also continued her placement in a residential facility.

One of the issues Ms Hickey may have to consider is whether to take legal action over delays in taking the girl into care.

After she was taken into care, she alleged that more than 12 named individuals in her local area had sexual intercourse with her.

She alleged she was abused by them in her bedroom after they came to her home when her mother was present.

A younger brother also made allegations of sexual abuse by family members.

Both children were assessed by a sexual abuse unit, which concluded their allegations were credible.

The girl's guardian has expressed the view that had the authorities acted earlier on concerns about the family, much if not all of the abuse, neglect and trauma suffered by her, could have been avoided.

The guardian said social work services were familiar with the family before the girl was born.

When she was two years old, a child protection conference had concluded there was a high level of concern about the family.

The girl's father left the home when she was aged four and there were increased concerns about the mother's ability to manage and safely parent the children.

The concerns included hygiene, school attendance, behaviour and the quality of care in the home.

The children were taken into care in 2010.

The girls' guardian believed there was an "apparent pattern" of professionals observing concerns about the family, putting supports in place, and when it was later acknowledged the supports were not effective, nothing was done.

Her case came before Mr Justice Kelly via an application to make her a ward of court as she was about to turn 18.

The court heard criminal proceedings have been initiated against the girl's mother and her maternal grandfather.