The mother of Merlin in the Elizabethan play The Birth of Merlin (published 1662, but written earlier), in whose composition Shakespeare may have had a hand. If so, it is possible that he was helped by W. Rowley (died 1626), although Rowley may well have written the entire play.
She was impregnated by the Devil, who came to her in human form. She was convinced that the father was a nobleman at Aurelius Ambrosius’s court until the Devil revealed himself again to her.
Her brother was named Clown.
The Birth of Merlin, or the Childe Hath Found His Father | Attributed to William Shakespeare and William Rowley, 1662