The 11-year-old joined her brother and royal relatives at the annual event

Credit: Getty; Rex USA

Lady Louise isn’t so little anymore!

Prince Edward‘s daughter, 11, was spotted enjoying the Royal Windsor Horse Show in Windsor, England, on Sunday, and it looks as if she’s grown up quite a bit since she made her grand appearance at the balcony in Buckingham Palace during Prince William and Princess Kate‘s April 2011 wedding.

On Sunday, the young royal was seen spending most of the day with her mother Sophie, Countess of Wessex, her father and younger brother James Viscount Severn, 7. Princess Anne’s son Peter Phillips brought his children, daughters Savannah, 4, and Isla, 3, along for the event, and they were seen playing with Louise and James on Sunday.

Lady Louise was dressed appropriately for the event, wearing an equestrian blazer, as well as leggings and brown riding boots. The adorable preteen has grown dramatically in the past few years, standing nearly as tall as her mother.

When Louise was 7, she served as a bridesmaid for Kate during the big royal wedding and was featured in several of the royal portraits.

Her appearance has changed in recent years, as she had a corrective operation in 2014 to fix a serious eye disorder.

For much more on life with Prince George and Princess Charlotte, pick up this week’s issue of PEOPLE, on newsstands Friday