Kate Middleton is celebrating her 40th birthday, and members of the royal family are sending their best wishes on her big day.

In honour of the Duchess of Cambridge hitting the 4-0 milestone on Sunday, Jan. 9, The Queen offered a greeting via social media.

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“Wishing The Duchess of Cambridge a very happy 40th birthday today!” reads the caption in a post from the royal family Instagram account, accompanying a photo of Duchess Kate and Elizabeth II sharing a laugh.

Duchess Kate also received a birthday greeting from her father-in-law, Prince Charles, and his wife, Camilla, Duchess of Cornwall.

“Wishing The Duchess of Cambridge a very happy 40th birthday today! 🎂,” reads a note from the Clarence House Instagram account, along with a photo of Kate and the Prince of Wales.