Kate then wowed royal watchers when she stepped out in a bespoke blue ruffled gown by Alexander McQueen, sporting the Royal Family Order of Queen Elizabeth II for the first time ever.
At Eugenie and Jack's wedding, Kate wore a bright fuchsia pink dress - a bold colour she has never been seen in before.
Royal fashion experts believe the Duchess' wardrobe change may be a first sign towards an edgier Kate, who is coming "back with a bang" as she settles into her role as future Queen consort.
Kaitlin Menza, co-host of the Royally Obsessed podcast, told Vanity Fair: "After that long break, she has certainly come back with a bang.
"She seems like she's in a more take-charge position. I'm beginning to see the person who's going to be the queen emerging."
Meanwhile, Susan E. Kelley, editor of the What Kate Wore website wrote: "I think this is where Kate gets to make her mark."
Celebrity stylist Rochelle White told FEMAIL that Kate's handover of her "princess in training" status to sister-in-law Meghan may also be behind the sudden change.
"She has been 'princess in training' for a while now, and now that Meghan has taken over the role, she is really starting to embrace her changing position.
"She looks relaxed and confident rocking this style of dress, which is very princess-esque, and shows off her silhouette post-baby."