there has been speculation that she wrote shakespeare's sonnets. robin p. williams presents a circumstantial case that mary sidney might have written the sonnets attributed to shakespeare, 17 of them urging her brother to marry and most of the others to her lover, dr mathew lister. williams also sees the lister relationship behind the play "all's well that ends well". williams acknowledges that there is no documentary evidence for the case, but notes that the detailed knowledge shown in the plays of sailing, archery, falconry, alchemy, astronomy, cooking, medicine and travel correlate with what we know of mary sidney's life and interests.