We were buying a birthday card for my mother in a shop in Edgbaston, Birmingham, when my then seven-year-old son James suddenly started wailing at the top of his voice.
Flailing his arms, he rocked backwards and forwards so hard in his wheelchair that I thought it would topple over.
James, who is quadriplegic, epileptic and severely autistic, hadn’t wanted to leave the house to go shopping and was now having a full-on tantrum. As he hit his head with his fist and bit his hand, I tried to calm him down by talking gently to him and hugging him, but all he did was bite and slap me.
As people started staring at us in horror and disbelief, my eyes filled with tears.
Dealing with a severely disabled child is exhausting at the best of times, but it was the 2006 summer holidays and all three of our children had been off school for weeks — James, his older brother Tom, then nine, and younger sister Elizabeth, then four. I was weary.
Trying to ignore the stares and James’s escalating howls, I grabbed the first card I could find and struggled to the counter to pay.
As I did so, the lady in front of me finished paying and turned to leave. Rather than avoiding eye contact, however, she handed me a bag containing what she had just bought.
It was a teddy bear wearing a lilac T‑shirt which bore the words ‘World’s No 1 Mum’.
‘This is for you. You are doing a wonderful job,’ she said with a smile, then slipped out of the shop.
That woman will never know how badly I needed to hear those words.
Indeed, unexpected moments like that sustained me through the darkest, most difficult hours of raising James, now 13 — days which drove me and my husband to the brink of divorce, made me consider taking my own life and cast a terrible shadow over the childhoods of his brother and sister.
I am 49 now. Until I was 36 I lived in what I thought was a normal world. I was a successful solicitor with a loving husband, a healthy toddler and a beautiful home. There was a lot to juggle, but I thought I was in control of everything.
I didn’t take much notice of people in wheelchairs. If I saw someone in the street with a mental disability, I lowered my eyes and moved on.