7x7.5 Typed note signed in black ballpoint ink by Mary Higgins Clark. It is a thank you note and is dated in 2000. In very good condition. Mary Theresa Eleanor Higgins Clark (December 24, 1927 – January 31, 2020) was an American author of suspense novels. Each of her 51 books was a bestseller in the United States and various European countries, and all of her novels remained in print as of 2015, with her debut suspense novel, Where Are the Children?, in its seventy-fifth printing.