But Erin's parents Kirstin and Jamie were told she might not live to see her first birthday.
Born with an extremely rare liver condition, her life was saved with a transplant when she was just six months old.
Doctors said she might not have lived for another week, had a donor not been found in time.
Erin is one of the lucky ones. Many children die waiting for a transplant.
The Children's Liver Disease Foundation says more parents are considering donating part of their own liver because of the shortage of organs for transplant.
Erin's mum Kirstin has backed the Evening Times' call for an opt-out system of organ donation to help drive up donor numbers as a national fundraising drive for chilhood liver disease gets under way today.
Kirstin, 32, from Carstairs in South Lanarkshire, said: "Anything that can improve the uptake and raise awareness is a good thing. We were lucky. We know of a lot of families, whose children haven't made it.
"Even if it had been another week Erin might not have made it."
Erin was born with the rare liver disease, biliary atresia, a condition in which inflammation develops within the bile ducts around the time of birth. This leads to bile duct damage, reducing the flow of bile, which causes scarring of the liver.
Only around one out of every 18,000 infants is affected.
Without treatment, such as a transplant, few children live beyond the age of two. Erin was transferred to a hospital in Leeds because Scotland does not have a paediatric liver unit and placed on the transplant list when her condition worsened.
Kirstin, who is expecting the couple's second child, said: "We were told we might be there for six months, but she didn't have six months.
"We got a call after eight days. She got a split liver and part of it went to an adult.
"We don't know anything about the family. We wrote them a letter about how we had lived in hospital and now we could live at home.
"She wouldn't have made it to her first birthday without it.
"I think a lot of adults don't realise they could help a child.
"The piece she got will grow with her so hopefully she won't need another transplant. Some children do need to have another transplant, if they get a bad infection.
"There are also quite a lot of risks with her medication, she's quite immuno-suppressed. She can't have vaccines for measles or mumps. If she gets a temperature we have to take her straight to hospital.
"But we try to let her do everything and she's just started nursery.
"She's got a line across her tummy and tells people she got that from being really brave."
Every day in the UK, two children are diagnosed with liver disease - more than leukaemia - and there is still no cure.
The family have received support from the Children's Liver Disease Foundation ever since Erin's diagnosis and have raised more than £30,000 for the charity.
Yellow-themed events will take place up and down the country today to mark Big Yellow Friday, the national awareness and fundraising day for the charity. Jane Asher is among the celebrity patrons who will be taking part.
Alison Taylor, from the charity, said: "Every day in the UK, two children are diagnosed with a childhood liver disease - more than childhood leukaemia - and there is still no cure.
"We take action against childhood liver disease by providing information and emotional support, funds for research and a voice for all those affected. In order to do this however, we rely on community fundraising for the majority of our income which is why Big Yellow Friday is such an important day for us."