Lady Melbourne was known for her political influence and her friendships and romantic relationships with other members of the English aristocracy, including Georgiana Cavendish, Duchess of Devonshire, Francis Russell, 5th Duke of Bedford, and George, Prince of Wales.

She was the youngest child and only daughter of Sir Ralph Milbanke, 5th Baronet, and his wife, Elizabeth (née Hedworth).

[3] The couple lived at Melbourne House in Piccadilly and Elizabeth quickly became a well-known figure in London Whig society.

[3] She was apparently untroubled by her husband's infidelity early in their marriage with the actress and courtesan, Sophia Baddeley, just as he came to tolerate her numerous love affairs.

[3] From the start of her marriage, the shrewd and coldly pragmatic Lady Melbourne cultivated friendships that helped her position in society, and her husband's career.

William, though admitting that his mother's private life was not blameless, called her "the most sagacious woman [he] ever knew" and remarked that "she kept me straight as long as she lived".

[3] Until this point, Lady Melbourne had enjoyed unrivalled success as a political hostess and quickly recognised that the young duchess, with a higher rank and better connections, would be a more valuable friend than a rival.

Only once, it is said, did they quarrel on the subject: this was in the strained atmosphere caused by the death of their eldest son Peniston, the only child whom Melbourne knew to be his own flesh and blood.

In 1782, Lady Melbourne became acquainted with George, Prince of Wales while visiting her son Peniston twice a week at Eton College.

[8] The relationship proved to be of benefit to Lord Melbourne, who was made Gentleman of the Bedchamber to Prince George at Carlton House.

[8] Lady Melbourne's fourth son George (born 1784) was widely believed to have been fathered by the prince, who acted as the boy's godfather.

[13] Although she approved of her son's marriage on social grounds, Lady Melbourne disliked Caroline intensely and their relationship was always bad.