Margaret Gallagher appeared at Letterkenny District Court in Donegal charged with harassing Theresa Tyrrell and her son.
Ms Tyrell and her son Gary received three cards in total which were sent anonymously in April 2017.
The letters made reference to her first-born child whom she had when she was a young woman and of whom her other son Gary was not even aware.
The matter was reported to gardaí and an investigation was launched into where the cards came from.
Detective Garda Alfie McHale managed to get a 19-digit code from the stamp on one of the letters and was able to trace it back to the shop in which it was sold. A trawl of CCTV footage of the shop identified Ms Gallagher, who is in her 50s, buying the stamps and, despite initially denying she sent the letters, she eventually admitted the crime.
She claimed she sent the letters after a fallout between herself and Ms Tyrell at the Chesire Apartments, a centre for adults with learning difficulties in Letterkenny.
The accused, of Croagh Patrick Avenue, Letterkenny, claims that Ms Tyrrell bullied her daughter who also worked at the Cheshire Apartments.
In her statement to gardaí, Ms Gallagher said shewas “really sorry” and did not realise sending the cards was a criminal offence: “I felt sorry for Gary but she made my daughter’s life hell. She got girls suspended from work but it was a stupid thing to do.”
The court was told that the Tyrrell family wanted the matter to be heard in public as it was the only way people would know what had happened to them.
Ms Tyrrell told the court that she denies ever bullying anybody at work and that she still works at the Cheshire Apartments.
Ms Tyrrell’s son Gary said the apology given by Ms Gallagher does not make any difference to him or his family.
“This is the first I have heard of an apology. It doesn’t make any difference, the hurt is already caused. I can’t understand why the defendant would try to ruin my life and destroy everything I have known to be true. Her solicitor said it was not out of revenge but I want to know why.”
Solicitor for the accused, Patsy Gallagher, said his client had no previous convictions and is “deeply apologetic” for her actions.
“The victim impact statement has deeply affected my client,” he said.
He asked for the case to be put back to allow for a probation report.
Judge Paul Kelly said this is a “deeply distressing case” and said the victim impact statements from Ms Tyrrell and her son are “heart-wrenchingly eloquent”.
He said: “I can only imagine the complete and utter turmoil it must have set off when Ms Tyrrell opened the first card and to wait and see the post and what it would say and how she would address it with her son who knew nothing of this until this happened. It is utterly incomprehensible how someone could sit down and write these materials and go and post them in Northern Ireland to throw people off the scent and do it over a period of time. I fail to understand the state of mind involved there.”
Judge Kelly adjourned the case until July 9 to allow for a probation report on Ms Gallagher.