"I first saw the Queen as a little girl of four and have been following her all of my life," Sheila says.
Her mother took her to see the changing of the guard at Buckingham Palace when they were living in London. It was while watching one of these events that Sheila became fascinated by the Queen.
"I saw Her Majesty sitting in the royal car," she says. "I remember she was wearing a yellow outfit, a white hat and white gloves.
"Since then I have been lucky enough to have met her on many walkabouts.
"My mother was a huge royal enthusiast and her enthusiasm rubbed off on me. That's how it started.
"I suppose that my interest was also due to the fact that I'm close in age to Princes Andrew and Edward."
"I was always interested in history at school so I started collecting royal memorabilia when I was quite young. I had pictures and guidebooks and later when I was a bit older I started to add more items to the collection.
"As my collection has grown over the years, I can't begin to tell you how many items I have, although there are other followers with larger archives.
"It's the photos that mean the most to me. I have over 400 now.
"My two favourites include one of the changing of the guard which I got when I was about seven years old. And the other is one taken of my late mother with Prince Charles in 2003."
Another key moment for Sheila was the 1981 marriage of the Prince of Wales and Lady Diana Spencer.
"Everything became bigger once Prince Charles married Diana," she says.
"The number of royal events I attended increased during that decade. I also met my friend Mary Relph at this time. Mary is from King's Lynn and another royal watcher like me."
Sheila and Mary have since been to many royal events together and received seats in the Diamond Jubilee ballot to watch events outside Buckingham Palace.
"It was my most poignant memory over the years as the Duke of Edinburgh had to miss some of the ceremony due to ill health.
"I remember thinking that the Queen looked very lonely without him at her side."
Sheila still goes to events whenever she can, although nowadays these tend to be mostly in Scotland with occasional trips to London or Sandringham.
"I've met the Queen many times over the years. She's got to know me pretty well.
"The most memorable and special meetings were when she stopped her Range Rover to speak to me once in a village near Sandringham in 2005 and in the grounds of Balmoral in July 2006.
"Sandringham is the one that I most recall as I was there with another royal watcher friend.
"Her Majesty was driving a Range Rover at the time. She recognised us both and asked whether we were going to be at the Sunday service the next day."
"When we heard that my mother was ill and dying of cancer, we told Her Majesty. She made a point of making an extra special effort to come over to speak to us everywhere we went.
"Just a few hours after my mum gave the Queen some flowers after the Maundy service in Liverpool in 2004, my mum was taken ill and sadly died a couple of weeks later.
"I think Her Majesty is a very special person who has devoted her entire life to serving this country and deserves the respect in which she is held all round the world."
Find out more about Queen Elizabeth II on BBC iWonder
For the past 50 years Royal Family watcher and fan Sheila Clark has been travelling around the UK to events attended by the Queen, meeting and taking photos of the monarch.