The Late Mr. Marcus Williams and Mrs. Jameelah Williams cordially invites... .... I've seen it written this way several times... or if possible just send it to her only... or him only.. if she is deceased.
The correct way to send a written invitation to a widowed woman is: Mrs. Bill Smith This honors the memory of her husband, and of their marriage, by continuing to use his name. The correct way to send a written invitation to a woman who is divorced is: Ms. Mary Smith, using only her own first name. If she has never been married, or if she is divorced and has resumed her maiden name: Ms. Mary Jones