How was Katharine, Duchess of Kent, related to King Charles?

Katharine, Duchess of Kent, died  at age 92 at Kensington Palace, Buckingham Palace announced Friday. 

The duchess was married for 64 years to the Duke of Kent, cousin of the late Queen Elizabeth II. 

Her husband, Prince Edward, Duke of Kent is the son of Prince George, (fourth son of King George V).

King Charles III is the son of Queen Elizabeth II, who was the daughter of King George VI (second son of King George V).

That makes Prince Edward (Duke of Kent) and Queen Elizabeth II first cousins (their fathers were brothers).

Therefore, Prince Edward and King Charles III are first cousins once removed. 

This made the Duchess of Kent King Charles's cousin-in-law as she was related to the monarch through her marriage to the Duke of Kent.

According to BBC, born as Katharine Worsley, from an aristocratic land-owning family in Yorkshire, the duchess became part of the Royal Family in 1961 when she married the Duke of Kent. 

Katharine became widely recognized for her compassionate public appearances, particularly at Wimbledon tennis championships where she would comfort defeated players. 

The palace statement praised her "life-long devotion to all the organisations with which she was associated, her passion for music and her empathy for young people."

The couple had three children: George, Earl of St. Andrews, Lady Helen Taylor, and Lord Nicholas Windsor.

King Charles and Queen Camilla joined other royal family members in expressing condolences. Prime Minister Keir Starmer also issued a statement of sympathy.

The duchess had maintained a relatively private life in recent years, focusing on charitable work and her passion for music education.