OPINION:
On Thursday morning, the woman known mononymously as Kate woke up and did the school run, ferrying her three children to their first day at their new school Lambrook. Did she then toast the start of a new school year with an extra large skim latte? Let's assume she did. No matter, it was a day all about new beginnings.
However, by the finishing bell rang, Prince William and his uncles and aunt were dashing to Scotland to be by the ailing Queen's side and at 6.30pm that night, sad news of Her Majesty's passing was announced by Buckingham Palace. Kate might have started the day a duchess but she finished it on the cusp of princess-dom and thus one giant step closer to the Crown. (On Friday night King Charles III formally announced that he was immediately making her husband the Prince of Wales.)
When Kate was, I'm guessing, trying to wrangle children, hockey sticks and brand new lunch boxes into her car last Thursday, she had no way of knowing that her life was about to change irrevocably.
Oh sure, now she's got a grander title than she possessed this time last week and she and William will soon be pocketing $40 million annually thanks to his newly acquired custodianship of Duchy of Cornwall. (Until now they made do, cough, the $4.2 million they used to receive from Charles.)
However, it was only in late August that Kate, William and their kids Prince George, Princess Charlotte and Prince Louis moved from London to Windsor, swapping their Kensington Palace apartment (all four storeys of it) for the comparatively modest four-bedroom Adelaide Cottage.
One of the factors that reportedly prompted the Waleses to head to the suburbs was the promise of the increased privacy and space they could enjoy living on the thousands of acres Her Majesty's Windsor estate. (Another motivation? To reportedly be nearer to the Queen.)
It had seemed like an excellent plan, a chance for William and Kate to give their kids one last good stretch of ostensible normality before the walls of the monarchy started to close in.
Sadly, fate intervened and the terrain of the prince and princess' life has now altered forever; being a duke and duchess is one thing but being the heir apparent and his wife is another entirely. In a stringently hierarchical organisation, the Waleses just got that much closer to the zenith.
A girl could get vertigo up there.
William and Kate, now face an increase in responsibilities and in duties, not only because they are now the holders of the 14th century Wales title but because the number of working royal family members has fallen. Again.
In the accession of Charles and his wife Camilla becoming Queen Consort, the Palace has lost two HRHs who can be dispatched to cheerfully open plaques and shake hands the length and breadth of Great Britain, not when the business of the State is calling.
If the King follows his mother's example, he will go through his Red Box of official government documents 363-days-a-year, only taking Christmas and Easter off, not to mention his weekly audience with the Prime Minister, investitures, and receiving new ambassadors and carrying out state visits.
All of this will take a lot of time and leaves only William and Kate as royal headliners to step in and to fill the gap.
There are also implications for the Wales' trio, Prince George, Princess Charlotte and Prince Louis, all of whom have now officially gotten "of Wales" tacked on the ends of their names.
After having been the scene-stealing stars of the Queen's Platinum Jubilee, the Wales Three look set to return to the spotlight, with the Times' royal editor Roya Nikkhah reporting that "In the coming days and months, their children are likely to be more visible at the 'big family moments' that accompany a change of reign."
If you think about it, the royal family is essentially one of the biggest marketing outfits in the world and there is no more sure-fire way of attracting rapturous publicity than wheeling out the oh-so-cute troika. Selling the idea of a hereditary monarchy is that much easier if the public is being fed a steady diet of photos of precious, young princes and a princess.
So too will the Wales kids be needed in the coming months and years to really continue to drive home the message of continuity and unity the palace has been busy trying to promote after you know-who belted off to America and discovered the catharsis of pummelling the royal family's reputation to Oprah.
For Kate, as a mother who has by all accounts strived to protect her children from the intrusive glare of the public attention and the press as much as is possible, this must not be a dismal prospect.
The new princess, keep in mind here, will be facing all this while carrying a title that comes with serious baggage. The last holder of it, Diana, to this day continues to cast a long shadow over the royal family. (Yes, Camilla was technically the Princess of Wales too but never once, for obvious reasons, used it.)
Over the weekend a source told the Daily Mail that Kate "appreciates the history associated with this role but will understandably want to look to the future as she creates her own path," a line that reads like it had been stuffed away in a drawer waiting for this very moment.
No matter Kate's plans to "create her own path", there is no getting away from the fact that the title is inextricably linked to suffering and tragedy, a legacy that only adds to Kate's growing burden here. Those three simple words – Princess of Wales – trigger an emotional response unlike any other that are still used by the House of Windsor.
Added to which in all of this, the 40-year-old now faces possibly even more relentlessly compared to her mother-in-law in terms of her style and work.
Yes, this day was always going to come, however, it would seem as if William and Kate had been hoping they had a little longer to cos-play suburban mum'n'dad; a little longer before history came calling.
Back in 2010 when William and Kate sat down for their engagement TV interview, he said of his fiance: "No one is going to try to fill my mother's shoes… It's about making your own future and your own destiny and Kate will do a very good job of that." For her sake, here's hoping he is right.
• Daniela Elser is a royal expert and a writer with more than 15 years' experience working with a number of Australia's leading media titles.