The Duke and Duchess may not celebrate their third wedding anniversary until Tuesday, but romantic Wills is well ahead of the curve: he presented Kate with a stunning wristwatch weeks before they went on tour. Both her £3,600 Ballon Bleu de Cartier watch, which is embedded with a sapphire to match her engagement ring, and a diamond eternity band, which she wears on her wedding finger, are thought to have been gifts from William. The Duchess of Cambridge, pictured during the tour of Australia and New Zealand, left, adores the stylish stainless steel £3,600 Ballon Bleu de Cartier watch, right, which was given to her before the tour by William 
 
 
 
 The brand carries a special significance for the couple. Happy Eater: George nibbles on Mum's expensive haircut 
 
 In fact, ‘gorgeous George’ has been so ravenous that at a tea party at Ayers Rock, Kate revealed that he has grown ‘an extra fat roll’ on his three-week trip down under. It is thought they will be catching up with the Middletons and the rest of their family, reuniting them with baby George to show them how much he has grown. Neither William or Kate have any official engagements today—in contrast to last year, when pregnant Kate spent the day on a visit to a children’s hospice in Hampshire and William was in Wales on duty as an RAF search-and-rescue pilot. Kate and Will have day to themselves to celebrate their third anniversary 
 
 Can it really have been three years?
– It may feel like you've been hearing about Prince William and wife Kate for a thousand years, but they've only been married for three, as of today. And she got quite an anniversary gift, the Daily Mail reports: Wills gave her a Cartier watch that cost upward of $6,000; it's embedded with a sapphire, to match Kate's engagement ring. He reportedly gave it to her before they set off on their three-week tour of Australia and New Zealand, and Kate wore it every day they were gone. The watch has another link to Princess Diana (who, of course, was the first owner of Kate's ring): Di also wore a Cartier watch, and once had one engraved for William for his birthday. Oh, and then of course there's the fact that the queen "is encouraging Kate to build up her own collection of Cartier items," the Mail notes. As for how the royal couple is celebrating their anniversary, officials say they're doing so "privately," according to the Daily Beast; the Mirror says they're expected to spend time with Kate's family. They were apart on their second anniversary, with William on duty as an RAF pilot.