Princess Eugenie shares a close bond with her mother, Sarah, Duchess of York, and the pair regularly champion one another's achievements.
The royal, 31, took to her Instagram stories on Thursday after author Sarah shared some triumphant news.
After expressing concern about an area of land, the Duchess said in an Instagram post: "We won! @BasingstokeGov councillors voted 9-1 to overturn plans for one of the largest warehouses in the UK which would have destroyed 67 ancient oak trees near my childhood home."
Eugenie was quick to reshare her mum's post and wrote: "Well done Mumma…" How sweet!
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It comes after the York family celebrated Sarah's 62nd birthday earlier this month, with Eugenie sharing some sweet family pictures to mark the occasion.
The Instagram snap showed Sarah and Eugenie embracing each other as they hiked through the Scottish Highlands. Mother and daughter were suitably dressed for the occasion with Sarah wearing a tartan jumper with a blue coat tied around her waist, while in her hand was a pair of red sunglasses.
Eugenie praised mum Sarah on Instagram Stories
Meanwhile, Eugenie wore a grey pullover, with a black button-up coat wrapped around her waist. Unlike her mum, she had kept her sunglasses on, rocking a pair of shades with a white frame.
The mum-of-one had a simple caption for her post, writing: "Happy Birthday to my dearest Mumma.. @sarahferguson15."
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Eugenie's birthday post for Sarah
Eugenie and her older sister, Princess Beatrice, wowed as wedding guests at the nuptials of Prince Philippos of Greece and Denmark and Princess Nina over the weekend.
The royal sisters were joined by their husbands, Jack Brooksbank and Edoardo Mapelli Mozzi.
Beatrice and Edoardo welcomed the arrival of their daughter, Sienna, on 18 September. Meanwhile, Eugenie and Jack's son, August, was born in February.
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