Although she is only 18-months-old, she has already had four operations at Yorkhiill Hospital, and has more surgey in store.
Now her dad Steve, in appreciation of all the hospital has done for her, has set himself the challenge of running 2013 kilometres in 2013 to raise cash for the hospital.
Steve, 35, said: "To look at Caitlin you would not know she has her challenges.
"She bounds about like any other cheeky, inquisitive 18-month-old toddler and her condition does not seem to impact her too greatly at the moment. She certainly tires us out before she tires herself out!
"I would be lying if I said we don't worry about the future, but we don't know what that holds and it is out of our control.
"So we try to be practical and just focus on what is in front of us, each check-up and each surgery."
Mum Marie, 32, had a normal pregnancy, but during labour Caitlin's heart rate kept dropping and doctors could not work out why.
A routine check when she was born showed that the baby had a heart murmur, which is not unusual in newborns.
Steve and Marie were hopeful Caitlin's heart would settle down, but 24 hours later she was taken to paediatric intensive care.
Marie said: "I still wasn't really worried at this point. We didn't think too much about it, to be honest. I was still in a bubble, having just given birth, and she looked so healthy.
"Caitlin was taken for a scan and the radiologist was very chatty at first but suddenly went really quiet and asked us to step into a different room.
"We had thought it was to give the other family in the room some space, but it turned out to be for us."
The scan showed Caitlin had the rare condition Truncus Arteriosus, where a baby is born with one large artery coming from the heart instead of two separate ones to carry blood to the lungs and body.
This means the heart has to pump harder, and there is no artery to carry blood to the lungs for oxygen before it travels back to the body.
The diagnosis meant the baby faced her first operation at just six weeks old.
Marie added: "The doctor was so matter of fact about the whole thing that we didn't really know what it meant – for her or us.
"I had her out everywhere and seeing everyone – we just got on with things, even though her heart was failing."
A first operation should have closed the open artery with a patch, but this failed to work and Caitlin had to be brought back for a second operation.
During an open heart procedure the surgeons made her a pulmonary artery from a cow's vein, but this has failed to grow with Caitlin, and is too small for her body.
So far she has had two open heart surgeries and two keyhole surgeries, each time at Yorkhill Children's Hospital.
Steve added: "Luckily Caitlin has bounced straight back every time so she doesn't give us too much of a chance to worry.
"She doesn't feel sorry for herself, so what right have we? We don't think about the 'what ifs' and just enjoy our time together like any other family."
Since her operations she had developed pulmonary stenosis, when the heart works so hard that the muscles thicken and block the right ventricle.
Marie, a full time mum, said: "The doctors say Caitlin keeps them on their toes. Every time she has had a surgery something has gone wrong – from operations being cancelled at the last minute to the time she had a febrile fit in theatre or once her heart stopped and she had to be resuscitated."
Caitlin now has to attend hospital every three months for check-ups, and Marie and Steve are waiting to find out what more doctors can do to help her heart.
But the family wanted to give back to Yorkhill – and Steve plans to run 2013 kilometres in 2013 to raise cash for the charity.
Bosses at his work, Standard Life, have promised to match any funds he raises.
Steve, a marketing manager, said: "There is simply no way of thanking the cardic team at Yorkhill Hospital enough for what they have done for Caitlin and our family.
"They offer so much hope and support, they are truly special people. It was always our intention of raising money for Yorkhill Children's Foundation to give a little something back and to support the wonderful work they do."
He added: "Before our experience with Caitlin I was guilty of taking for granted the work the NHS carried out. However, I cannot express in words the impact the surgeons, doctors and nurses have had on our lives in providing care for Caitlin.
"Quite simply, without them Caitlin would not be with us today and for that we will be forever grateful. We cannot speak highly enough of the support we have received.
"To us Yorkhill is an amazing place."
Steve will be running the Glasgow Men's 10k on Father's Day, June 16, to help raise cash for the Yorkhill Children's Foundation.
Kirsten Sinclair, Fundraising Manager at Yorkhill Children's Foundation, said: "We have all been really touched by Caitlin's story and the challenge Steve has set himself.
"We would like to give our sincere thanks to him for his support. The money Steve will raise in this fantastic challenge will go towards helping children all across the country and beyond.
"Without support from generous people like Steve a lot of what we do would not be possible."
"We'll be supporting Steve all the way to the last finish line and we hope this wonderful dedication inspires many more people to have a go and raise money for Yorkhill."
l To donate, go to http: //uk.