In the Duchess' case, it seems likely that it'll be the one that once belonged to the Queen Mother.
"Richard Palmer, a Daily Express royal reporter shared, "[It was] just fantastic to see the Queen just talking normally and say what she thought rather than what the spin-doctors thought she ought to be saying". With everything she is doing, how is she keeping up? At the Gatcombe Park Horse Trials last month, she took breaks from playing with big cousins Savannah Phillips, 8, and Isla Phillips, 6, to visit Lena in her stroller. Sign up for our newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!
In related news, the Duchess of Sussex is now on her maternity leave and she will return to her royal duties in October. They can be spotted watching Princess Charlotte, and Prince George play soccer in the gardens, and the royal siblings have also been seen racing in the Kensington Palace Gardens and hunting for spiders. Prince William is next in line for the throne after his father, Prince Charles.
Kate Middleton has reportedly been put under Queen Elizabeth's wings for training as her kind of heir. According to Princess Diana's former butler, Paul Burrell, the mother-of-three will don Queen Elizabeth's 1937 diamond consort crown by Garrard & Co.
And, of course, every Queen needs a crown.
When the time comes, Kate Middleton will be crowned at Prince William's coronation in Westminster Abbey as the Queen Consort.
Prince William and Kate Middleton have a lot of change coming in their extended family soon, with Prince Harry and Meghan Markle expecting their little one any day now. Upon Victoria's death the stone became part of the Crown Jewels and has been used on a number of crowns including that of Queen Alexandra and Queen Mary. At the time being, Catherine will don tiaras like the Cartier Halo Scroll she wore when she got married in 2011. Markle also did a similar thing a year ago when she tied the knot with Prince Harry.