This 115-year-old tradition involved giving shamrocks to the Irish Guards on St Patrick's Day.
Kate has been accompanying Prince William to the ceremony since their marriage in 2011.
Why, you ask? Because Kate wanted to prioritize spending time with her children.
And Kate takes her motherly duties seriously - she's known for being hands-on with her kids.
But that doesn't mean she shirks her royal duties - she celebrated St Patrick's Day with Prince William and the Irish Guards.
In fact, Kate is now the Colonel of the Irish Guards, a role she took over from Prince William.
All in all, Kate's decision to break with tradition is a pleasant and relatable shift from the usual royal rigmarole. Long live the Queen (of motherhood)!