Eliza Williams is a character mentioned in Sense and Sensibility, she never appears in the book.
She is the ward of Colonel Brandon and was seduced and impregnated by an unamed man, who deserts her. After she has her child, on her deathbed, she asks Colonel Brandon to take care of Beth. He sends Beth to the country to be raised, and admittedly he gives her too much freedom. She becomes pregnant by John Willoughby , a flirt and a rake. News of the illegitimate child reaches his patron and aunt Lady Allen, who disinherits him. Willoughby has to marry an heiress, and he chooses Miss Grey, a society debutante with a dowry of £50,000, a fortune.