When her doting mother, Louisa O'Donovan, found her daughter covered in bruises she assumed Shauna had hurt herself while playing.
The 9-year-old had never been sick before, so as his symptoms worsened, Ruygsek, 37, became worried.
She said: “In July 2014 I started getting bruises and I knew something was wrong.
“We took her to the doctor and at the start of August she was rushed to Limerick and then St Mary's Children's Hospital in Crumlin.”
The consultant told the family that Shona had aplastic anaemia (acute bone marrow failure) and required an urgent whole bone marrow transplant.
It's more common in places where there is water pollution, but is rarely heard of here.
Shauna is the youngest child in the country to be diagnosed with the rare disease.
Her twin brother Caoimhin came to her aid and offered himself as her desired marriage partner.
Mr Ruysieck, from Corofin, County Clare, revealed: “Every time there is talk about this he
Would be helpful.
“Then in October, when he found out it was fatal, he told Dr. Cranlin he was hoping to get a match.”
While his family was in shock, little Caoimhin switched into hero mode.
She added: “He really wanted to help her at all costs. If he could have gone out of his way for her, he would have. She's his little world and he adores her.”
December 18th was the D-day when the family would find out whether Shauna would accept or reject her brother's bone marrow.
The concerned mother of two recalled the ordeal her son went through to save his brother. “When the doctors came back with the bag of bone marrow they had taken from my son before sending it off to the lab for cleaning, he came out in pieces inside me,” Ms Ruygsek said.
“When they told me they would have to go inside me and poke me 50 times to get my bone marrow, I almost felt sick.
“What made it even worse for Caoimhin was that the doctors were giving him codeine as a painkiller, which he was allergic to and no one knew, which made him even more ill.
“The poor kid could barely hold his head up for days.”
Doctors literally used a long needle to extract bone marrow from the boy's body. That afternoon, his sister, Shauna, underwent the transplant, but thanks to the twin, she turned out to be a perfect match.
Shauna's blood levels dropped rapidly after her diagnosis, so it was crucial that she found a donor quickly.
She underwent the transplant while she was still healthy, so her chances of success were higher.
The consultant told the family that the chance of success was six in 10 if the child was healthy.
The twins' grandmother Joy Long, 58, from Ballybofey, Co Donegal, nominated her grandson for the Pride of Ireland's Brave Child Award.
“He was brave enough to come forward and after he was stabbed 50 times he was torn to pieces,” Joy said.
He was dizzy and never complained. When I asked him how he was, he always said, “I'm fine, I'm fine.” I just
I hope she's okay. He's very brave because he was always worried about his twins.”
Now, almost three months after her surgery, Shauna is doing well.
Her twin brother was unable to play for up to a month after donating his bone marrow but has now returned to Gaelic sports and football.
Former Derry GAA star and transplant activist Joe Brolly paid tribute to Caoimhin online.
The RTE football panellist, who donated a kidney to a friend, tweeted: “This 9-year-old boy from Clare saved his twin sister's life by donating his bone marrow. He says he's been 'in a bit of pain for a week'.”
Meanwhile, recalling the brave acts Caoimhín did for his sister, his mother said his bravery knew no bounds. Mr Ruysieck added: “The way he dealt with Shona's diagnosis was better than most adults would have acted. He was very clear about what he wanted.”
“We haven’t been able to spend Christmas together and since November he has stopped taking me and his dad Kevin.
“He said, 'Mum, I think we should go to Granny and Grandpa in Donegal for Christmas because you and Dad should be with Shona in hospital because she's going to need you.'”
“I cried all afternoon. I couldn't believe a nine-year-old boy could be so selfless and humble – he's wise beyond his years.” The proud mum says it's a challenge for Shauna to get up at 6am to go to Clanlyn Hospital.
She added: “Her brother gets up before her every morning and has breakfast with her, getting her out of the house.
“Even on snowy mornings, he would get up multiple times to load the car for Shauna.
“I don't think we could ever repay him for all he's done for us. He's our shining light.”
- Time is running out so nominate your unsung hero online at prideofireland.ie or visit the Lidl Roadshow Tour Bus at the Lidl Store, Mahon Point, Co. Cork this Sunday from 10am to 5pm.
