Flown to Starship, she had a caesarean birth, and although Eva required heart surgery when she was seven and a half weeks old, she was born with no brain damage.
The surgery took six hours and involved patching up the hole in Eva's heart.
Eva was born with only one artery, so another conduit was also inserted, Mrs Galvin said.
Although she got through the surgery, complications resulted in Eva developing violent seizures afterwards.
"There was damage to the right hand side of her brain - she was having seizures and at one point had a cardiac arrest.
"She got through that and they managed to find a medication to treat the seizures, and once she had made it through 24 hours without a seizure they weaned her off that medication."
The doctors thought the brain damage would affect Eva's left side and her mobility, said Mrs Galvin.
"On Christmas morning though she squeezed hubby's finger with her left hand - we were all nearly in tears - that was pretty neat."
After defying all those odds Eva has gone from strength to strength and will celebrate her second birthday in November.
For the Galvin family and others in similar situations, life could be challenging, but making it easier over the last six weeks had been the presence of new family support worker Angelina Gorst.
Mrs Gorst said she saw her role as three-fold.
"I do what I can to support the families, and then I connect them with other families going through similar things and also connect them with resources in Hawke's Bay that can help."
She covered the East Coast region from Gisborne to Dannevirke, where 200 children with heart conditions lived.
"Heart Kids is there to give lifelong support to these kids and their families."
Mrs Galvin said Heart Kids was a not-for-profit organisation and Mrs Gorst's role was paid for through fundraising, and that she was doing an "amazing" job.
"When you are going through this stressful thing you don't want to unload to friends and family all the time - it's nice to have an outlet.
"Getting the families together to share our knowledge is also really invaluable - you can't put a price on it."
● For more information about Heart Kids and the support available go to www.heartkids.org.nz