Lorraine Kelly's 32-year marriage, becoming a grandma and appearing on Masked Dancer

Lorraine Kelly has been at the helm of one of the country's most popular daytime programmes for decades. And, as all long-serving personalities are wont to do, she has starred in her own documentary.

Airing tonight (Wednesday) on ITV - her spiritual home after all this time - the 64-year-old gran, originally from Glasgow, has taken part in the programme to mark her 40 years in showbiz. Lorraine Kelly: 40 Unforgettable Years is, it says in the TV guide: "a tribute to the much-loved presenter and journalist who joined TV-am in October 1984, and became one of British TV's most popular broadcasters".

This morning's episode of Lorraine also saw the star in reflective mood as she talked to hosts Christine Lampard and Ranvir Singh about her career so far.

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She said: “It just feels like it's gone by in a flash and I've been so incredibly lucky because, mainly with the people that I work with, all of these incredible people, my great team. It's a joy to go into work every morning, an absolute joy.”

Lorraine began her journalism career on the East Kilbride News, turning down a university place to study English and Russian to join the newspaper, before joining BBC Scotland as a researcher in 1983. In 1984, she joined TV-am as an on-screen reporter covering Scottish news, and in 1990 she began her presenting career on Good Morning Britain, before getting her own show, Lorraine, in 2010.

Her husband Steve Smith has been there almost as long as the cameras. The couple has been married for 32 years after meeting while Steve was working as a cameraman on TV-am.

Speaking to Woman and Home, Lorraine once said: "He walked into the TV-am office 28 years ago where I was working as a reporter and he was part of the crew, and I thought, 'That'll do, I'm having that.'"

The duo were friends for a year before they began dating.When they were out filming for work in Glencoe, Lorraine previously said: "We were staying in a tiny hotel in the middle of nowhere and I got him incredibly drunk on tequila before making my move. The way I remember it is that I leapt on him like a ninja and he had absolutely no defence!"

Lorraine and Steve married on September 5, 1992 at Mains Castle in Dundee. Two years later, daughter Rosie was born.

Lorraine says of her husband: "His idea of hell on earth would be at something like a premiere. It would be like having needles stuck in his eyes.

"That does help. It must be very odd being with someone who enjoys walking down a red carpet."

Rosie, 29, gave birth to the couple's first grandchild Billie on August 29. Lorraine shared her excitement in the comments as she gushed over the wonderful family news on social media: "I have been BURSTING to share this wonderful news with you! Baby Billie is an angel and I'm so proud of @rosiekellysmith and @stevewhite94 who will be the best parents. I'm delighted to be Granny Smith and can't wait to go on adventures."

This morning, Lorraine repeated a career highlight - her Masked Singer performance of Kylie Minogue’s Padam Padam while dressed as an owl in the Lorraine studio. Friends and family also came to the studio wearing T-shirts with her face on.

On the topic of the documentary she said: “This is going to be so lovely to show Billie (her granddaughter), when she’s old enough I can do that as well as the documentary tonight. I can actually show her, it’ll be like the most amazing photo album, it just feels like it’s gone by in a flash."

Lorraine Kelly: 40 Unforgettable Years is on ITV1 at 9pm on Wednesday, October 1