When she was only 18 months old, her mum Debbie spotted a problem with one of her eyes.
It turned out to be a very aggressive form of cancer, which would have claimed her life had it spread to her brain.
The only solution was immediate surgery in Temple Street to remove her eye. Now, aged two, Emily has gone from strength to strength.
Speaking about their year of rollercoaster emotions, Debbie and her husband Robert are thankful that Emily is recovering and adapting well.
"We pulled out all the stops at Christmas and made a huge effort just to make it that bit extra special for her," said Robert.
"It meant so much to us that she came through the operation. She still has to have regular check-ups under anaesthetic to ensure her other eye is clear, but so far, so good," he added.
The cancer that invaded Emily's eye is called a retinoblastoma, an often painless condition that makes it even more deadly because it can grow unnoticed in the eye.
Sometimes it is spotted when a photograph is taken and one eye shows a red reflection from the retina -- which is normal -- but the second eye gives back a white reflection.
Speaking about the disease, Emily's surgeon, Prof Michael O'Keefe, said retinoblastomas are the most common eye tumour in childhood.
"If they are found in time the sight can be saved, if not the child can lose sight and the eye. Once that cancer gets into the optic nerve it can travel to the brain or into the bloodstream and it runs rampant," he explained.
But with regular check-ups, Robert and Debbie are hoping Emily has a bright future.
"We have started Emily in Montessori school now and her confidence is really coming on. She wears an implant with a prosthetic eye which is a great match," said Robert.
At the time Emily was operated on the proposed children's hospital at the Mater site had been rejected by An Bord Pleanala. It is only in recent weeks that the St James's site was picked for the new €500m facility.
And even though it will take around five years to build and come on stream, Robert and Debbie are pleased that a decision has finally been made.
"Maybe it won't make much difference to Emily until she's much older, but for future families who face the difficulties of children's illnesses, it will be good to have a well functioning hospital," said Robert.