Gladys Deacon was considered a stunning beauty in her youth, but all her glamour was gone when she died in a mental asylum in 1977, almost 100 years old. So were those wild ambitions of moving from a position of American wealth to English nobility, which had led her onto a dangerous road of dreams at an early age: She was 14 years old when her lifelong envy was triggered by another American girl, Consuelo Vanderbilt, getting married to The Duke of Marlborough. Being of the highest nobility he was considered a real "catch", although he wasn't a very pleasant character.
The Duke and Duchess of Marlborough, Consuelo Vanderbilt and Charles Spencer-Churchill, 9th Duke of Marlborough
Gladys wasn't only beautiful, but also very smart and charismatic. Maybe that was why she succeeded in becoming a friend of the young, American-born Duchess, Consuelo, who wasn't very happy in her high society marriage into nobility. Actually, she hadn't been interested in marrying the somewhat somber Duke. Also, she had been in love with a young American, but her very ambitious mother was against such a non-classy marriage, so she conceded in giving up her true love to make her family happy by becoming a full-class Duchess. That meant that she spent many unhappy years in England, but at least her American money saved Blenheim, the castle of the noble Marlborough family, which her son eventually inherited.

Gladys
had her own worries, and they were of a peculiar nature: The German
Crown Prince, Wilhelm, was one of the numerous men who fell madly in love with her. When that happened, it became a big sensation, broadcasted by numerous newspapers. Yes, the sensation grew to such length that someone
started to sell a cut-out-doll over her likeness.
Vilhelm
Many others than the German Crown Prince extolled her beauty. One of them was the French writer, Marcel Proust, who wrote: "I never saw a girl with such beauty, such
magnificent intelligence, such goodness, and charm".
The exceedingly ambitious (and presumably always envious!) Gladys might have made a "career move" by accepting the proposals of e.g. Prince Caetani or Radziwill. She wasn't in love with either of them, but when her younger sister, Dorothy, married prince Radziwill she got enraged as she found that she had been outdone by her in some kind of secret "sister-competition". Something she couldn't abide!
It's my impression that she was totally engulfed in all of these more or less secret competitions for female status that was so very important to many/most women because that was their only accepted outlet for their ambitions on a personal level. Had she not felt that way, she might have been much happier, but that was what she had been brought up to feel. When another one of her sisters were introduced in high society, she saw to it that she herself outshone her in the typical Gladys-way she had attained as her personal style.

Being considered a stunning beauty wasn't enough for her vanity: She saw flaws where others saw perfection, so she went to Paris to have cosmetic surgery of her nose. Alas, she became one of the many who suffered from botched surgery, as the wax she had had injected into her nose melted and, sort of, twisted her facial traits. Poor Gladys had entered a trail of misery, although she succeeded in having some of the melted wax removed: She got scars and other disfigurements.

However, when she was almost forty years old she succeeded in obtaining that noble title she had pined for since she was 14: She got married to The Duke of Marlborough, who probably had been her lover for years, even before his marriage to Consuelo was ended. Unfortunately for Gladys, the marriage soon proved not to be what she wished for, as it put a stop to her life as an international socialite. Becoming the new Duchess of Marlborough meant staying at the family seat of Blenheim, being bored and restless. Also, there were no kids, but she underwent a couple of dangerous abortions which must be part of her wishes as she made some utterances against having kids.

At one point, she mocked the Duke by talking about all the men of noble and royal birth she had slept with, all the time hoping that sex wouldn't lead to a pregnancy. Maybe that was why he sort of harassed her out of his life in 1932. He died of cancer two years later, and she turned into a rather weird recluse whom her family had committed into a mental asylum when she was 81. No matter what she did, she didn't succeed in getting out, but stayed until she died.
https://www.theshot.com/actors/facts-about-gladys-deacon-the-socialite-turned-recluse-188-1719587956
https://nypost.com/2018/08/25/these-four-american-brides-were-sold-off-to-foreign-lords/
https://www.news.com.au/lifestyle/real-life/true-stories/the-story-of-gladys-deacon-the-1920s-socialite-who-became-a-recluse-and-died-in-a-mental-hospital/news-story/c94037af12d6ec5d9b0ce6bce5526d6e
https://www.oxfordmail.co.uk/news/8839177.gladys-deacon----eccentric-duchess-blenheim-palace/
Wikipedia