Her son, Murray, has a rare form of epilepsy which was blighting his childhood with multiple seizures, hospital admissions, missed school days and had left his parents fearing for his life.
We thought the battle was won when the then Home Secretary Sajid Javid made cannabis oil – the substance on which Karen Gray and her family were pinning their hopes – legal in November 2018.
But we were wrong. Despite changing Murray’s life to the extent that he is now seizure free, his family are still unable to access the treatment on the NHS.
Like many others across the UK in a similar situation, they have to meet the often staggering costs of medicinal cannabis themselves. For Murray, the private prescription and costs can be more than £1,000 per month. The strain, the financial burden, is all on the families.
It wasn’t supposed to be this way. When Sajid Javid agreed in 2018 that medicinal cannabis would be legal for use in the United Kingdom, we all believed that parents would no longer be forced to watch their children suffer when they knew a treatment was available.
Finally, I thought, the government seems to get it. I am afraid to say, however, that's just when progress stalled. It is heart-breaking.
In the intervening years, they have been forced to source medication themselves, sometimes travel abroad to collect it, challenge the medical authorities and faced rejection of repeated appeals for NHS prescriptions for whole plant-based cannabidiol.
That is why I am leading a debate in Westminster today to remind the government that it is time to put our money where their mouth is.
With so much red tape and inflexible guidelines, too many patients face being left alone, helpless and simply unable to afford life-changing treatment.
In fact, just three NHS prescriptions for the type of medical cannabis that is life transforming for Alfie Dingley, a boy just like Murray, have been issued since cannabis oil was legalised.
Just three. Clearly guidelines are not empowering doctors to do the job they want to do and provide the best possible care for their patients knowing they have the support of the establishment.
The explanations offered also fall far short of what all of us should be able to expect from the government.
Medical trials do not offer any hope, they would be no use for children already benefiting from the drugs. It would mean coming off the treatment they are on, perhaps for a placebo, and potentially placing them at risk.
Moreover, clinical trials are not appropriate with this form of medication which can involve changes in the balance of ingredients for individual patients.
And then critics point to the fact that there is a medicine, Epidiolex, available on prescription for two rare forms of childhood epilepsy in the UK, but my understanding is that it is less effective for many sufferers.
The type of medicinal cannabis they are desperate to have is, scientists claim, effective for 95 per cent of children.
And for those who still would wait for clinical trials, scientists say that there is an overwhelming body of observed evidence of the efficacy of cannabis oil.
I have seen, first-hand the difference that it could make. Medical cannabis oil has transformed the life of Murray Gray.
When his mum Karen first came to me, he was a very unwell little boy who was, as I explained, constantly in and out of hospital with dozens of seizures, and his family were worried they could lose him.
Now, since being prescribed cannabis oil, he is seizure free and a happy youngster who plays football with his dad and told me everything I needed to know about dinosaurs when he visited my office. This medication has given him a life he otherwise may not have had.
Just as when he was Home Secretary, I believe it is time that Sajid Javid, now Health Secretary, personally intervenes.
It is time he closed the huge gulf between what the government promised and what it has delivered.
This shouldn't be a political football kicked between party politicians and, for the most part, we resist that.
I say this because I was one of more than 100 MPs from across the political divide – the Liberal Democrats, Conservatives, Labour and Green MPs – who a little over a year ago wrote to the former Health Secretary to demand action.
Nor is the debate any longer about proper use or otherwise of cannabis oil – the evidence that it is life-changing for those in need is already overwhelming. So then, it appears that the debate comes down to the willingness of the government to pay up.
The clock is ticking, however. For many families, the Grays included, there will come a time when they cannot afford the medicine their loved ones need. We can no longer wait for the creaking bureaucracy to turn.
So, my appeal in Westminster will be straightforward. Until a more widespread solution for prescribing can be agreed, and it must, the government should save these families from the pain and pay for prescriptions.
Surely any person, when the quality of life for a child is on the line, would quickly come to the conclusion that paying up is the right thing to do?
I am optimistic that the minister will agree.
Christine Jardine is Liberal Democrat MP for Edinburgh West