Anna Corrigan was in her mid-50s when she made a shock discovery about her family.
The Dubliner was raised as an only child, but in 2012 she found out she had two older brothers her mother had never told her about.
She also discovered both boys were born while her mother was a resident of the Tuam mother and baby home in County Galway.
Anna has spent the past eight years trying to confirm their fate.
She still does not know for sure what became of them, nor if they are among the children buried in the mass grave in Tuam.
“I need to know what happened,” Anna told BBC News NI.
The campaigner wants a full exhumation of the Tuam babies’ burial site, with DNA testing to identify all those buried in the plot.
Anna’s story was central in bringing the Tuam babies controversy to worldwide attention in 2014.
Her mother, Bridget Dolan, was among thousands of women who gave birth in secret in Irish mother and baby homes, in an era when the scandal of pregnancy outside marriage often destroyed lives.
It was a secret Anna’s mother took to her grave – Bridget died in 2001 without telling her new family in Dublin about her painful past in her native County Galway.
In 2012, more than a decade after her mother’s death, Anna began to research her family history and her parents’ involvement with social services.
Records from the Barnardos children’s charity showed her mother gave birth to two boys more than four years apart while she was resident in the Tuam home.
According to their official birth certificates, Bridget’s first son, John Desmond Dolan, was born on 22 February 1946.
Her second, William Joseph Dolan, was born on 21 May 1950.
Anna was told both her brothers died as babies, but no death certificate was ever issued for William, and John’s death was not medically certified.
The few official documents Anna has been able to access left her with more questions than answers.
The Tuam home was inspected in April 1947 and according to a redacted report obtained by Anna, living conditions were extremely difficult.
Health problems were noted among several of the home’s 271 children, with some described as “wasted,” “wizened” and “delicate”.
An inspector described then 13-month-old John Desmond as a “miserable, emaciated child with a voracious appetite”.
The two-day inspection also revealed the building was overcrowded, housing 90 more residents than it was designed to accommodate.
Like most single mothers, Bridget Dolan had to leave the home 12 months after giving birth – without her baby.
She got a job as a housekeeper and evidence suggests she sent five shillings a month to the home to help provide for her child.
But in 1947 there was a fatal outbreak of measles in the home.
Baby John’s death certificate states he died on 11 June 1947, citing measles as the cause.
In the blunt, insensitive language of the era, it also describes John as a “congenital idiot”.
Anna wants to know why her brother, who was born weighing a healthy 8lb 9oz, was both hungry and “emaciated” just over a year later.
She fears malnutrition and neglect were a significant factor, but despite an inspector noting his ill health, Anna was told there are no medical records for John.
The informant on his death certificate was a long-term resident of the home who had no medical qualifications.
There is even more mystery over William’s birth and death records.
Anna does not know how her mother ended up in the same difficult position three years later, but Bridget was pregnant with her second son when she was readmitted to the home in 1950.
Certificates show William was born in a Galway hospital on 21 May that year and was baptised four days later.
According to the order of nuns who ran the Tuam home, the Sisters of Bon Secours, William died on 3 February 1951, but there is no death certificate on record.
The only available documentation is a note in the nuns’ ledger which said that William “died” – it does not provide any reason or medical explanation.
Strangely, the nuns’ ledger also showed a different date of birth, stating William was born on 20 April 1950.
The inconsistencies left Anna questioning whether William may have been adopted, and if there is any chance he is still alive.
Concerned by the missing and conflicting documentation, Anna contacted gardaí (Irish police).
She reported William as a “missing person” because his death was not registered. She also asked them to investigate the circumstances of John’s death.
BBC News NI asked the Garda if they had investigated either case, but they would not comment on individual cases in advance of the Mother and Baby Home Inquiry’s report.
A spokesman for the Sisters of Bon Secours also said they could not comment before the publication.
Shortly after Anna found out about her brothers’ existence, she was put in contact with the amateur historian Catherine Corless, whose painstaking research into death and burial records helped uncover the mass grave at Tuam.
The pair brought their concerns about baby burials to the local papers in 2014, but frustrated by its lack of impact in the media, Anna turned to the Irish Mail on Sunday.
She told her story anonymously to reporter Alison O’Reilly, and within days Tuam was making headlines around the world.
The controversy led the government to set up the Mother and Baby Homes Inquiry, which by 2017 confirmed significant quantities of human remains had been found in an unmarked grave in Tuam.
At that point, Anna decided to go public and her story became the subject of a book.
But even now she still does not know the full truth of what happened to her brothers.