Jane, Duchess of Gordon. However, just like the Harriet to Jane's Georgiana, Eglantine, or Betty as she was known, proved to be just as interesting of a character.
Betty and her sisters were brought up by their mother, Lady Maxwell in a tenement in Edinburgh. The girls were known to be a bit wild (especially for daughters of a baronet) and rode pigs down the street with all the local children (hence the term 'piggy-back rides'). While Jane seemed to have curtailed the majority of her wild personality as she successful moved up the social ranks, Betty never seemed to lose her fire. She married Thomas Dunlop in 1770 who was made the 5th Baronet of Wallace shortly afterward. The marriage only lasted eight years; the couple legally separated on the grounds of Thomas's cruelty. However, I wouldn't be too surprised if Betty didn't give back as good as she got. Around this time she was summoned before a magistrate to answer for assaulting a female companion. She had to answer the same charges in 1793 when she assaulted a servant. Lady Wallace was a honey badger.
In 1793 she snuck into the House of Commons to watch a debate. Since women were forbidden from the public gallery Betty disguised herself in mens' clothing and managed to see much of the debate before she was discovered and consequentially kicked out. After her separation, she moved to London and took up the playwrights' pen. Three of her plays seemed fairly well-received in the late 1780s, with Sarah Siddons even taking up one of the roles. Her 1795 play, The Whim: A Comedy, however was banned by the licenser for an unknown reason. One can only hope it was because it was too racy.
Betty had a few close calls in her adventurous life. In 1789 she decided to travel to France to take the spa waters for her health, not thinking, perhaps this wasn't the best time to do so. After speaking her mind about the current political situation to, erm, the wrong people, she was arrested and accused of espionage - a crazy accusation considering Betty would have been the worst spy ever. She luckily managed to escape the situation with her head intact.
Not deterred by the continent after that experience, Lady Wallace seems to have spent the remainder of her life traveling in London through Europe. She died in Munich in 1803.