As a senior member of the Royal Family, the Duchess of Cambridge's working life is filled with duties and engagements.
But if it wasn't for her royal status, she could well have ended up working at one of her relatives' highly successful businesses.
From her mum Carole to her brother-in-law James Matthews, Kate's family seemed to have amassed tidy fortunes thanks to their entrepreneurial spirit.
So how exactly have they made their money? We take a look...
Carole Middleton
One of the most successful Middletons in business is Kate's mum Carole, who heads up the firm Party Pieces.
She was born in London and grew up in a relatively normal family in Southall, before becoming cabin crew with British Airways.
While working there, she met her husband Michael and the couple went on to have three children - Catherine (more commonly known as Kate), Pippa, then James.
In 1987, she set up Party Pieces from her kitchen table after she realised she could make money from creating party bags.
It is now a highly successful mail-order party supplies business and she and husband Michael are self-made millionaires.
In a rare interview, Carole has talked about her business and said she has no plans to slow down despite turning 67 yesterday.
And during the chat, she revealed that the lightbulb moment for creating her business came as she struggled to find any decent party supplies in the shops for Kate's fifth birthday party.
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She told the Daily Mail : "All I could find were basic clown plates.
"I realised there was a gap in the market for partyware that wasn't too expensive and which looked good, so decided to design my own. I took some prototypes to various High Street retailers and was turned away."
However, despite being turned away from retailers, Carole knuckled down, set up her business and began handing out leaflets at her daughters' school - and the firm took off.
Even Kate, Pippa and James were models in some of her early marketing materials.
She added: "Thirty-five years later, I'm launching the Party Pieces collection. I suppose some things are worth the wait! So rather than slowing down, this is an exciting new chapter for me. I think I'll always be interested in party trends."
Pippa Middleton
Kate's sister Pippa shot to fame following her role as her sister's bridesmaid at her wedding to Prince William.
She graduated from the University of Edinburgh with a degree in English Literature and briefly worked in PR.
After her sister's wedding, she was flooded with work - earning money from writing a book on hosting parties called Celebrate and having her own column in the Waitrose food magazine.
Recently, it was revealed that the mum-of-two has a registered business called Pippa's Playground, which according to Hello! is " listed as a business of 'other human health activities', covering hydrotherapy, medical massage, speech therapy, chiropody, homoeopathy, chiropractic practices, acupuncture and more."
In 2020, Pippa and husband James Matthews bought Bucklebury Farm - a rundown petting zoo and deer park close to the mansion where Kate's parents live in Berkshire.
And now they've submitted plans to the local council to build an indoor play barn for children, a cafe and a farm shop with outdoor seating.
It is thought that the couple and their business partners aim to spend around £800,000 on the upgrade.
James Matthews
Pippa's husband James Matthews, older brother of Spencer Matthews, is also very wealthy with the Daily Mail estimating his net worth to be around £2billion.
He skipped university to become a securities trader at investment bank Spear, Leeds & Kellogg, now part of Goldman Sachs.
In 2001 he set up investment advisory firm Eden Rock Capital Management, where he is now the chief executive. By 2007, it was reported the firm was managing over £1billion in assets.
As well as his investment firm, James is also a managing director of the Glen Affric estate in the Scottish Highlands.
The 10,000-acre estate is owned by James' dad David Matthews, who holds the title Laird of Glen Affric, which will pass to James upon his death.
James Middleton
James is several years younger than Kate and other sister Pippa, and is the only son of parents Carole and Michael Middleton.
In 2011, he was given a starring role at Kate's wedding to William as he gave a bible reading.
He was the co-founder of Boomf - a personalised gifts company - which has recently been sold after the Covid-19 pandemic took its toll on the firm.
In 2020, James, who married wife Alizee last year, then launched launched Ella & Co, a dog food firm that specialises in using natural ingredients.
And last November he scooped the prize for Pet Professional of the Year at the Pet Industry Federation awards.
Gary Goldsmith
Kate's uncle Gary Goldsmith - a brother of Kate's mum Carole - is also a millionaire in his own right.
He began a career in IT and became a director of IT recruitment company Computer Futures within six months.
He later sold his shares in the firm to make his fortune.
