Philomena Lee has described revelations about the Tuam mother and babies as "absolutely appalling".
Ms Lee gave birth in Sean Ross Abbey, Co Tipperary to a child who would go on to become a senior legal counsel to two American presidents.
Her son Michael Hess, who she was forced to give up for adoption in 1952, died from AIDS in 1995. He would have been 65 this year if he had lived.
He visited Sean Ross many times looking for his birth mother, but the nuns there, who knew where Ms Lee lived, refused to connect mother and son.
Her story was turned in the critically acclaimed film, Philomena, released in 2013. Judi Dench, who played her, received an Oscar nomination for the role.
Ms Lee (83), said the relevations of Tuam brought back many of her own memories of her three and a half years in Sean Ross.
She was also contacted by Mr Hess's former partner Steve Dahllof, who had heard about the Tuam mother and babies home story.
“It (Tuam) was awful. I thought, ‘Oh my God, did it happen in our place’. We never knew what happened in these homes. It is so horrific,” she said.
“After Anthony (Ms Lee’s son) left the week before Christmas (1955), the nuns got rid of me three weeks later because I could not stop crying as Anthony was gone.”
Ms Lee said she and the mothers in Sean Ross Abbey did not question what happened to the remains of children who died there.
“We were just young teenagers really. Everything we were told, we believed in.We firmly believed we had committed a sin,” she said.
“We did not think to even query what happened the babies. We had no idea what went on. We were never asked to pray for anybody.”
Ms Lee said she felt lucky she was finally able to trace what happened her son though he died before they were reunited, but thousands of mothers who were forced to give up their children for adoption would not be so lucky.
She suggested the State should formally apologise to mothers who were incarcerated in institutions and who lost their children as a result, though she said it might be too late for many of them.
“They should be allowed to track down their children if they are able, but for a lot of them the records are gone.”
She also said the commission currently investigating 12 mother and baby homes including Sean Ross Abbey should be extended to all such homes including the Protestant ones.
Ms Lee said she was unimpressed with Taoiseach Enda Kenny’s speech last week in the Dáil. “I don’t think too much of it. It is too late saying things like that. It may be what a lot of people want to hear. They should just something about it and get the commission involved.
“I keep hearing, ‘those were the times’. I believed that at the beginning myself, but that is not an excuse anymore.”
