Most mothers want to nest in domestic seclusion once a baby arrives. It's nearly impossible to imagine what it must be like to be wrenched from that cocoon by the glare of a thousand flashbulbs.
Fortunately, Kate has an extraordinary resource to call upon in times of duress: the Middleton clan. Nothing helps a new mum more than personal experience of a happy childhood and her own mother being on hand to help replicate that security.
Some have criticised the suggestion that Carole Middleton may be present at the royal birth - in part because William's work as a search-and-rescue helicopter pilot could have prevented him from being at Kate's side speedily. Fear and panic are the enemies in childbirth, and few things will make you feel safer than having a trusted relative there to support you.
But when it comes to royal births, Diana, Princess of Wales - the mother-in-law Kate never met - was the true frontierswoman.
Diana was the first mother of an heir presumptive to choose hospital over home (or palace) when she plumped for the private maternity wing at St Mary's in Paddington; a decision Kate has emulated.
Diana broke with tradition in many other respects. She took baby William with her when she and Charles toured Australia and New Zealand in 1983, rather than leaving him at home with a nanny. And she dispatched her toddler son from Kensington Palace's patrolled borders to nearby Mrs Mynor's Nursery School. She didn't want William to miss out on key childhood treats, taking him and Harry go-karting, to rugby matches, the cinema and McDonald's. She was spotted queuing with both boys to see Santa at Selfridges.
She also escorted her sons to shelters for the homeless and hospices, keen for them to recognise their privilege.
Despite Diana's devotion to her sons, she relied on nannies to fulfil her royal obligations and often felt jealous of them. She couldn't call on her mother, Frances, to fill the gap because, while their relationship was mostly fond, it was riven with complexity. In 1967, Frances left Diana's father, Earl Spencer, for Peter Shand Kydd. She fought her former husband for custody of their four children, but there was little judicial sympathy in those days for an adulteress and Spencer won. Diana's confidence was badly dented, and she and her brother Charles (the current Earl Spencer) struggled to find lasting romantic happiness as adults. The fractured and fractious Spencer clan never offered any real refuge to the young Wills or Harry.
Kate knows the value of her parents' loving union and the stability it afforded her. Carole stayed at home with her children in their preschool years, and her daughter looks determined to show the same hands-on spirit.
Insiders believe that once William's paternity leave is over, Kate will spend a chunk of time at the Middletons' new Berkshire manor house to get the benefit of Carole's wisdom - thus also ensuring that the child knows a life free of footmen and curtsies. The new heir will be the first to enjoy the company of commoner aunts, uncles and grandparents on equal terms with royal relatives.
You can't help hoping that Kate and William will continue to kick out the boundaries of protocol in all directions. What new mother wouldn't like to see the Duchess of Cambridge at a toddlers' group in a church hall singing I'm a Little Teapot? It was just this kind of formative experience that helped to foster Kate's girl-next-door ease.
She attended her local primary school in Berkshire and was also an enthusiastic member of the local Brownie pack. I can't imagine any better preparation for a future generation of monarchy than a couple of years at a friendly state school - more useful than incarcerating a royal bairn at a South Ken private prep stuffed with the offspring of bankers and oligarchs. It would be a considerable innovation if a baby grew up to join a normal Cub or Brownie pack.
The litmus test of the normal parent will be best met if the Duke and Duchess are pictured struggling to install their first baby car seat in a family hatchback, before shipping in a Nasa scientist to work it out for them.
Where William and Kate can really challenge the orthodoxy, however, is with their choice of godparents. Look at the photos of Prince William's baptism and you see a coterie of Charles' royal cousins and aristocratic pals: King Constantine of Greece, Sir Laurens van der Post, the Duchess of Westminster, Lord Romsey and Lady Susan Hussey.
Meanwhile, Diana sits smiling awkwardly between the Queen and Queen Mother, holding her son without a true friend in the room.
Let's pray the Duke and Duchess can avoid a pan-European royal knees-up and that Kate will be free to choose a couple of her closest friends (or her sister Pippa) as moral guardians for their first-born.
