Queen Elizabeth's Daughter-In-Law Almost Died While Giving Birth To The Royal Family's "Secret Weapon," Who Turns 21 Today

Lady Louise Windsor was once called the Royal Family's "secret weapon," and as the daughter of the Duke and Duchess of Edinburgh turns 21 on Nov. 8, it's frightening to think that both she and her mother came very close to losing their lives in 2003.

Louise—who, as Prince Edward's child, is a granddaughter of the late Queen Elizabeth and Prince Philip—is the eldest of Edward and Duchess Sophie two children. The duchess experienced a normal pregnancy, but on Nov. 8, 2003, she started to experience "crippling abdominal pains," per the Daily Mail.

After arriving at Frimley Hospital near her Surrey, England home, doctors realized Sophie was experiencing an acute placental abruption—an experience that can be fatal for both mother and baby due to extreme blood loss.

Per the publication, Sophie "was reportedly just 15 minutes away from dying in the emergency room" during the incident and lost "nine pints of blood through internal bleeding."

Tiny baby Louise, who weighed in at just 4 pounds, 9 ounces, was born via emergency c-section and suffered from a rare eye condition called esotropia, causing her eyes to look in different directions. She would go on to have three separate surgeries for the issue over the years.

The premature baby was rushed to a London hospital, as Frimley didn't have a neontal specialist unit. Meanwhile, the duchess—who was "sedated, alone and distressed at being apart from her baby"—was in serious condition.

Devastatingly, Prince Edward was carrying out royal duties in Mauritius and was unable to be by his wife's side through the ordeal. The prince wasn't able to get to his family until the next day, and per the Daily Mail, "went as white as a sheet" when he realized the extent of the situation.

Duchess Sophie was forced to spend 16 days in the hospital away from her baby as she recovered from the traumatic birth. Queen Elizabeth allegedly paid a secret visit to Sophie in the hospital, which was unheard of at the time.

Years later, the Duchess of Edinburgh would return to the same hospital that saved her life to open its neonatal unit, stating (via Hello!) "The service you can provide can literally make the difference between life and death. I can attest to that."

Today, as Louise turns 21, she's been called "a credit" to the Royal Family. Like her cousin Prince William before her, she's a student at the University of St. Andrews in Scotland. And like her father, Prince Edward, Louise shares a love for theater.

She also inherited a royal passion from Prince Philip; the college student is an accomplished carriage driver and competes in numerous horse shows.

Down-to-earth Lady Louise—who has a summer job at a British garden center— is also a member of her university's Officers' Training Corps. If she pursues a career in the military, she would become the first female British royal to do so since Queen Elizabeth.