Battered and bruised by the gigantic wave which caused so much devastation, the couple count themselves lucky to be alive.
Kim especially is still recovering from the physical injuries of that horrifying day and both still suffer from "flashbacks" to the time when they were separated from Isabella as well as from each other in a tragedy which gripped the world.
But they were reunited with each other, as well as with their little daughter, and eventually flew home to their 10-year-old son Oliver, who had decided not to go on that fateful family Christmas holiday.
The days that followed included a touching funeral for little Isabella at St Oswalds Church in Ashbourne but not only that, a resolve by the couple to mark her memory in some way. And so the Isabella Peatfield Memorial Fund was formed, capturing the imagination of not only numerous local people but many more donors from as far away as the USA and South Africa.
A staggering £20,000 was raised in just a few weeks and Kim and Tristan decided to return to Sri Lanka to ensure the money was spent where it was most needed.
It was a decision not taken lightly, but the couple agreed: "We just had to go back, it was something we had to do, it was a pilgrimage if you like."
The return trip was harrowing but rewarding and Kim and Tristan have come home with a resolve to continue their work in raising money for the people who need it most, centring their efforts on a hospital, an orphanage and a home for the disabled.
"We just had to go back, but did not realise how harrowing it would be," said Kim. Tristan added: "We went back to the same hotel, but it was flattened, with only rubble remaining and it was startling to see some of our possessions and Isabellas still lying there."
Their first destination was Tangalle, where they had been spending a lovely family holiday until the tsunami struck and Kim was swept away and washed up more than two miles away. She was found lying on the road, injured and distraught, by Franz, originally from New Zealand and now living in Tangalle. He undoubtedly saved her life by taking her home and dealing with her wounds.
And when he was sure she was out of danger, he went looking for Tristan, found him and took him back for an emotional reunion. Franz is now running the Tangalle Hospital Trust to re-build the hospital and is one of the first people the couple wanted to see and to talk to on their recent return.
They wanted to thank him and offer their help through some of the money which they took out to Sri Lanka from the many Ashbourne area people and other donors who have added to the Isabella Fund.
The couple were reunited within a couple of hours not the three days as claimed in some national newspapers and Kim particularly will bear the scars of the tsunami through a nasty leg wound, which is now, thankfully, healing.
It was while still out in Sri Lanka after the tsunami had struck that Kim experienced first hand the terrible conditions in local hospitals and this was just one of the reasons they wanted to help Franz in his efforts.
Conditions are extremely basic not even mosquito nets for the beds and the toilets are certainly not up to any western standards.
The childrens ward is to be dedicated to five-year-old Isabella and Kim and Tristan are already planning their next trip later this year to help Franz refurbish the ward. There will also be a plaque in her memory and this is one way in which the couple hope to achieve something which is good and ongoing, through their own personal tragedy.
About £5,000 should cover the cost of refurbishing the ward and it is hoped that about 40 local workers who have since lost their jobs at the hotels will carry it out under the direction of an English businessman out there.
During a 50-mile ride up the coast to Galle, they saw nothing but devastation, but called in at one of the many refugee camps, one that they thought was being organised by the Sri Lankans themselves. There were 60 families in that particular camp and many of the families are now sharing tents and queuing for hours every day for their basic needs.
"We just asked them what they wanted and they gave us a shopping list and we went and loaded the car up with whatever we could get," said Tristan, explaining that money goes a long way out there, where local people live very simply and the average wage is about £25 a month.
While still in Tangalle, Kim and Tristan were reunited with Lanca, a local woman who worked at the hotel, but who lost everything when the tsunami struck. They are hoping that Lanca will act as their representative to co-ordinate how the money they have raised can best be used.
For that is one of their aims to carry on raising money in Isabella name and use it directly to benefit the local people of the area where they had stayed.
Not only have thousands of people lost their homes, they have also lost their jobs and livelihood and Kim and Tristan feel that if they can help fund projects which will encourage the locals to refurbish whatever they can, they will be keeping them in work and helping to create some order out of all the chaos.
The orphanage they chose to help is in Galle and the couple say that childrens homes in Sri Lanka are, quite simply, heart-breaking places, reminiscent of Dickensian England. The children are the forgotten citizens, devoid of any love or attention.
They visited a state-run orphanage which is being totally refurbished with new beds, cots and play areas. Work is well underway and the children no longer live in such terrible conditions and Kim and Tristan have pledged money to do the outdoor playground which will be dedicated to Isabellas memory.
But the very sad fact is that although the building work is progressing and the place is both cleaner and safer, the children are still living in an institutionalised environment. There are few experienced carers and the youngsters, aged from 0 to five, are often left for hours on end.
The couple went shopping to buy each of the children a new outfit in a bid to give them some identity and Kim said: "Ideally, we would love to be able to fund a fully qualified nursery nurse, or perhaps two, to go out there from this country to work in the orphanage."
She added: "Isabella attended the Mulberry Bush in Ashbourne for four years and we know the care she received there and all the activities which she took part in, it would be nice to give the orphanage something of that same atmosphere."
One of the couples most harrowing visits was to a home for the "disabled." Before the tsunami, children with any kind of disability, however mild would be institutionalised out of sight, out of mind seeming to be the motto.
These homes were locked and residents often tied to their beds and when the 40-foot wave swept through the home, they were trapped, with nowhere to run. What was worse, if anything could be worse, in the following days, the homes trustees ran off with all its funds and when aid workers arrived, the residents were living in appalling, filthy conditions, many dying in their beds.
Once again, Kim and Tristan asked what was most needed and on their "shopping list" was a freezer, which they managed to buy. One of the residents is Trevor, who has lived there for 26 years and is now running the home to look after his fellow residents.
All the rotten bedding has been thrown out, the place has been de-fumigated and they are receiving vital medical supplies. Apart from the freezer, Kim and Tristan also bought new crockery, books and pens and the promise to continue sending help in the future.
"We decided to talk to the News Telegraph about our trip as we wanted all those people who have donated money to the fund to see exactly where it is being spent," said Kim.
Tristan added that they also wished to thank the hundreds of people who sent them cards, letters and cash after Isabella died.
"We have received many from people we dont even know and money has even reached us from as far away as the USA and South Africa it is wonderful the response we have had," he said.
It is obvious that the family are still coming to terms, not only with their tragic loss, but also with their own frightening experiences in the tsunami, yet they are determined that Isabellas memorial fund will help with much needed work on the ground.
Kim and Tristan will also keep in touch with friends out there and know they will have to go back to see what progress is being made. It wont be a choice of whether they wish to go back they have to.
Emotionally however, they will be better prepared the next time and are hoping that in a few months time they will see that some progress is being made, although the couple agree it will take years for new homes to be built and life to get back to something resembling normal.