Maria Molyneux, Lady Sefton, was born Maria Margaret Craven, daughter of William Craven, 6th Baron Craven, and Lady Elizabeth Berkley. She married William Phillip Molyneux, 2nd Earl of Sefton, in 1792. Her husband was known as Lord Dashalong because of his fondness for fast driving. He was one of the founding members of the Four-In-Hand Club. Lady Sefton was one of the Lady Patronesses of Almack’s. (It is possible that her mother-in-law was one of the original founders of Almack’s Assembly Rooms, around 1765.) The eldest of the 1814 patronesses, as reported by Captain Gronow, she had likely held that position well before the younger set came on board as both she and her husband were socially prominent. Lady Sefton sponsored Mrs. Fitzherbert in London society, so clearly she was a prominent, influential figure. Even so, there is very little information known about her.
Sadly, there seems to be no portrait of Lady Sefton available, although several have been mis-identified as portraying her.