I was just 18 when my Aunt Mary died. The family had a difficult time with papers because her legal name was Marie. After all that trouble, I started signing everything with my legal first name, middle name first initial and then last name. I’ve never had any problems and will continue this practice till I die. DH was born at home but has a birth certificate and signs his name just like I do. 99% of our friends do not know our legal first names, we go by our nicknames. Doctors and dentists call us our by our legal names.