The “sisterly bond” between Kate Middleton and Sophie, Duchess of Edinburgh was on full display for Remembrance Sunday on Nov. 10, and royal biographer Ingrid Seward said Kate considers Sophie the older sister she never had.

The Duchess of Edinburgh attended a special charity event on Monday, marking the 60th anniversary of Wellbeing of Women at PwC's offices in London. In her role as patron of the women's health charity,

Catherine, Princess of Wales has always been a big sister figure. She was one year old when her little sister, Pippa Middleton, came along, and five when her baby brother, James Middleton, was born. Their relationship with one another only seems to have strengthened as they've entered the public eye,