Seventh sounds like he or she might have a decent shot at the top job, especially as recent changes to the law mean boys have no advantage over girls.
But in reality Baby Sussex is never going to be the monarch, barring a large asteroid hitting England while her parents are in Australia.
It’s possible the child will not even be a prince or princess. That title, which comes with the “his/her royal highness” honorific, is granted at the will of the sovereign – but is usually reserved for their children and grandchildren.
The Queen may bend the rules, though, as she did for William and Kate’s children. If they don’t get the HRH tag the children of Harry and Meghan won’t be left title-less.
At birth, they will automatically be a Lord or Lady Mountbatten-Windsor, and a son could be an earl.
The Kensington Palace announcement confirms weeks of speculation from royal watchers about why the Duchess was not joining Prince Harry on his Sydney Harbour Bridge climb set for Friday.
Instead, the Duke of Sussex will be accompanied by Prime Minister Scott Morrison along with Invictus Games competitors, to raise the Invictus flag ahead of the games opening on October 20.
It also confirms what eagle-eyed watchers of Friday’s wedding of Princess Eugenie suspected, after Meghan wore a loose fitting navy coat for the nuptials. When she didn’t take off the jacket in the church, speculation of a cover-up ensued.
The rumour mill continued on Monday morning when the pair touched down in Sydney and Meghan was photographed carrying a stack of folders in front of any potential bump.
Eager Australian royal watchers will get their first glimpse of the royal baby bump when the Duke and Duchess attend their official welcome on Tuesday morning at Admiralty House.
From there, it’s on to Taronga Zoo for the opening of a new science and learning institute with NSW Premier Gladys Berejiklian, two koalas and their joeys.
The couple will then attend a Bangarra Dance Company rehearsal at the Sydney Opera House, and do a public walk around the forecourt before ending the day with a reception back at Admiralty House.
with Helen Pitt
Jenny Noyes is a journalist at the Sydney Morning Herald. She was previously a writer and editor at Daily Life.
Nick Miller is Europe correspondent for The Sydney Morning Herald and The Age