“Tristan is three months seizure free now. He is a complete devil. He’s getting into mischief, everything you would expect from an active healthy three-year-old.
“He has been able to come off seven medications while before if we tried to wean him off any kind of drug he would end up in hospital.
“He is doing so well now. He is counting on his fingers, he’s singing his ABCs and he’s eating well, which is in sharp contrast to previously when we would have sat at a table for hours trying to get him to eat.
“It has completely changed his life. He’s doing great. He gets physio, speech language development, as he had when he was in Ireland.
“Basically they believe he is thriving. Whatever challenge they put in front of him, be it puzzles or other games, he can do it.”
Comparing the development to what he was like a year ago she said: “He was never left alone in a room even while sleeping as we would have had to have a camera on as he was having up to 20 seizures a day.
“He was getting black eyes, bloody noses and chipped teeth from drop seizures.
“Since December, since he started cannabis he has never once had a drop seizure.
“He has never once been admitted to hospital and he was in hospital at least once or twice a month.
“The longest time was when he was in hospital for a month when he would get seizures of up to an hour long.
“He needed oxygen, suction machines, rescue medication and we had to bring them all with us. It took so long to load up the car if we were going anywhere.
“Now if we are going shopping as long as I have the cannabis oil , just a few drops of that if anything happens and he is grand. It’s amazing, absolutely amazing.”
Yvonne said they can’t go home now that Tristan is making such good progress because they cannot bring back his medicine from the US.
She added: “We can’t leave the country with it. We want to try and get this made available in Ireland for everybody else who needs it.
“It is too good for people to miss out on this and have their children suffer when they could have something as simple as a few drops of oil to help them.”
Yvonne, who was speaking to Patricia Messinger on Cork’s 103 FM, said they are working with various bodies to try and speed a process up whereby they will be able to return home by Christmas with the medication.
Her older son Oscar, who will be four next week, is also with them in Colorado.
She said: “He talks about going home to see his grandparents and to sleep in his own bed. He is missing his daddy.”
When Yvonne appeared on RTE a national poll revealed that almost 80 per cent of people supported legalizing cannabis for medical use.
She also launched an online petition on Change.org to get people to support the cause.
She is in contact with members of both the Irish and American governments as well as the medical profession and whole plant cannabis medicine producers to try and find a way to get the family back home with the oil.