My grandmother (still living) had her last name legally changed In Illinois around 1948. My mother's birth certificate indicates my grandmother's maiden name as the new last name, however I need a government document certifying that my grandmother, with her original name, is the person who gave birth to my mother. Where/How could I find such a document? My grandmother got married after her name change, so her certificate shows her marrying with her new last name. I need this for a genealogy-related foreign legal matter.

