Máiría Cahill has welcomed a review into how Northern Ireland's Public Prosecution Services handled complaints by her and two others that concluded they were let down.
The person with overall responsibility for the service, Barra McGrory, has made an apology to the three individuals involved.
The review was carried out by Sir Keir Starmer, a former Director of Public Prosecutions in England and Wales and an Australian barrister, Katherine O'Byrne.
Five years ago three people, including Ms Cahill, made reports to the police of alleged sexual abuse, dating between 1997 and 2000.
Charges were laid against a number of individuals between 2010 and 2012 - some involving sexual abuse allegations and some IRA membership.
The cases were split into three trials.
Owing to various matters, none of the trials had been heard by the start of 2014.
Ultimately all three complainants withdrew their evidence, citing frustrations with the court process and the prosecution.
Verdicts of not guilty were entered in respect of all charges.
Ms Cahill welcomed the findings of the review and said that she would like to see its recommendations implemented quickly.
Speaking on RTÉ’s Six One News, she said the wait of four years had been horrendous and that she felt let down by Sinn Féin and the republican community.
She said that she is not calling for any resignations, but would like to ensure that victims of sexual abuse are treated properly and with care in the criminal justice process.
She said her legal representative was looking at whether to bring a lawsuit against the DPP.
"It has been horrendous for all of us and I recognise the hurt of the other two complainants/victims, also because four years is just a completely unacceptable amount of time for anybody to have to wait,” Ms Cahill said.
“And this report, I think, is a vindication of the fact that it was not my fault that the court cases collapsed."
The key findings of the review:
-The three complainants were let down by the PPS and counsel
-Communication with victims and witnesses was variable and inadequate
-Failure to communicate contributed to a loss of faith by the three complainants in the PPS conduct and handling of the cases
-Given the failings in this case, it was almost inevitable that first AA and BB and then MC would pull out of the process. Each was prepared their allegations at the outset, but as their cases became increasingly weakened and delayed, their willingness to continue understandably diminished
-The overall delay in the sexual abuse prosecution was unacceptable. It was regrettable that the listing date of the sexual abuse trial was postponed on a number of occasions and that delays were not more robustly opposed
-There was a failure by senior PPS staff and counsel properly to analyse how to treat the membership and investigation evidence in the sexual abuse case
- The decision to proceed with the membership charges was not taken and endorsed at a sufficiently senior level in the PPS. Nor was sufficient consideration given by the PPS staff and counsel to the potential impact of the membership cases on the sexual abuse case
-The time taken to reach decisions to prosecute in the membership cases was too long
Sir Keir Starmer also said: "the outcomes of the cases may not have been different if particular decisions had been taken."