Meghan Markle's (pictured) half brother Tom, 51, has revealed Prince Harry's girlfriend was set on the road to stardom by their father's lottery win when they were younger

She may have won the heart of a prince, but if Meghan Markle does tie the knot with Harry, as expected, it would just be the latest – if most substantial – stroke of good fortune in an extraordinary life.

Today, her half-brother Tom gave The Mail on Sunday an uniquely personal insight into his sister's background – and revealed for the first time how her incredible ascent was made possible by an unlikely twist of fate: a lottery win.

He told how their father, also called Tom, scooped $750,000 (around £565,000) in a lottery when Meghan was nine – a secret windfall that helped her to pursue dreams of fame and stardom with the 'laser focus' that has taken her to the top.

'If Meg marries Harry she'll have won the lottery of life but dad winning the lottery helped us all,' said Tom Jnr, 51.

'That money allowed Meg to go to the best schools and get the best training. Meg is someone who has always had laser focus. She knows what she wants and she doesn't stop until she gets it.

'She was always the family's princess but now she's going to be a real princess and I couldn't be more proud.'

Sitting in a diner in his tiny hometown of Grant's Pass, Oregon, Tom's life could not be more different to that of his 36-year-old sibling.

A towering 6ft 3in, like his father, he works as a window fitter and lives in a modest rented cottage with his fiancee Darlene, 36.

His face is ruddy from the Oregon chill and he is dressed in a stained T-shirt and workmen's overalls.

Meghan, 36, rose to fame after landing a role in TV detective show Castle in which she played a killer who dressed as Sleeping Beauty (pictured)

Last week, Meghan finished filming her seventh – and reportedly final – series of her hit TV drama Suits.

Rumour has it that she and her two rescue dogs will move from Toronto, where Suits is filmed, to London to be closer to her Royal boyfriend of 18 months.

Her body double Nicky Bursic added to the speculation on Friday with an Instagram post wishing the actress 'all the happiness in the world'.

The Mail on Sunday has also learned that both ITV and the BBC are preparing documentaries on Meghan for what one insider called the 'inevitable' engagement announcement.

Tom and his sister Samantha, 53, are the product of Tom Snr marriage's to Roslyn, whom he met in 1964 after moving from his native Pennsylvania to Chicago to work as a lighting director for a local television station.

Samantha, who is estranged from her family, was born in 1964 and Tom Jnr arrived two years later.

The marriage crumbled when he was seven. A few years later Tom Snr made the move to Hollywood and began working on shows such as Married With Children, and met a make-up artist called Doria Ragland.

Soon they were married and in 1981 Meghan was born.

'From the start she was the apple of my dad's eye, his princess,' Tom Jnr says.

'He called her his angel. She twisted him around her little finger.'

The Suits star is pictured as a baby with her half brother Tom, now 51, in Alburquerque, New Mexico. He spoke to Mail On Sunday about his sister's rise to fame and how their father's lottery win was what propelled her to stardom

The family moved into a bungalow in the middle-class Woodland Hills area of Los Angeles: 'Dad was a workaholic,' Tom recalls.

'Like Meghan, he has an incredible work ethic. Emotionally he's shy and can be cut off. He had a room which was locked that no one could enter. He needed private space. He says little, but was besotted by Meg.'

Tom Sr, now 73, loved comedies such as Benny Hill and Monty Python and 'has a quirky sense of fun', his son says.

'Meg and I grew up in a home where practical jokes were Hollywood productions.'

After watching a horror film Tom Snr carefully rigged up the children's bedrooms with fishing line: 'Drawers were opening in the middle of the night. We were terrified,' he laughs.

'Another time he filled the room with fake smoke and poured coins on to the floor for us to hunt.'

The siblings grew up on set: 'Dad worked all the time so he was always taking us to the studio.

'Meg grew up watching Hollywood work. There was never any doubt in her mind what she wanted to be.'

Tom Snr was earning good money, about $200,000 a year, when Meghan was in junior school.

He sent her to Hollywood's private Little Red Schoolhouse, whose old students include Elizabeth Taylor.

He and Doria split in 1989 when Meghan was eight but the family stayed close: 'We would see each other all the time.

A young Meghan is pictured with her father, also called Tom - a snap she posted on her Facebook page recently

'I stayed with Dad, Meg was with Doria. I'd go to her school productions. When you saw Meg on stage, even as a kid, it was clear she was going to be a star. She came alive.'

In 1990, Tom Snr won the lottery. Officials at the Californian lottery could find no official record of the win, but both Tom Jnr and another relative confirmed it.

'Dad rang me one day and told me to come over. There was a lump on his bed under a blanket. I pulled it back and saw stacks of money there. My first reaction was, 'What did you do?' He started laughing and said, 'I won the lottery!' '

The money helped send Meghan to the $16,000-a-year Immaculate Heart Catholic School, one of LA's finest, followed by Northwestern University where she studied drama: 'Meg won scholarships to other universities but she wanted to go to Northwestern so she did,' her brother adds.

'The money helped.' Yet last year Tom Snr declared bankruptcy, which his son blames on the poor investments made by a business partner.

The spotlight Meghan's romance with Prince Harry (pictured at the Invictus Games in Toronto) has shone on the family has not been all positive. Last year her brother Tom was arrested after a drunken altercation with his fiancee

Tom proudly watched his sister work her way up the Hollywood ranks, with a role in the TV detective show Castle in which she played a killer who dressed as Sleeping Beauty.

'She never lost focus, she worked so hard to make herself a star. When she sets her mind to do something she gets it.'

Tom says he and Meghan drifted apart after 2011, the year their paternal grandmother Dorothy, died and Meghan went to Toronto to start work on Suits.

But he says: 'There was no big falling out. Suits took her to a whole other level of fame.

'She got new friends, mixed in fancy circles. I was married and living my life. We stopped being close.'

Tom says the family remains estranged from Samantha, who is writing a tell-all book Diary Of A Pushy Princess.

He told the newspaper: 'I'm speaking out because I hate people thinking I'm the black sheep of the family.' His sister Meghan is pictured with the Prince at the closing ceremony of the Invictus Games in Toronto, Canada this year

'She's trying to cash in,' he says. 'Samantha wasn't there much when Meg was growing up.'

The spotlight Meghan's romance has shone on the family has not been all positive. Last year Tom was arrested after a drunken altercation with his fiancee.

All charges were dropped but he says: 'I'm speaking out because I hate people thinking I'm the black sheep of the family.'

His father now leads a quiet life in Mexico and 'just wants to be left in peace to enjoy retirement'.

But will he walk Meghan down the aisle? 'Isn't that something all fathers dream of?' Tom Jnr says. 'He'll do anything for Meg.'

Meghan will reportedly spend Thanksgiving on Thursday in Los Angeles with Doria, 61, who has already met Prince Harry.

As for Tom, he'll be busy planning his own wedding – which is sure to be a far more modest affair than his sister's.