My Grandma was always known as Margaret Ann, her Sister called her Annie and my Grandad called her "Peg". When I eventually got hold of her birth certificate, her name was Marguerite Ann.
My Mother went by the name of Kathleen Rose and always signed as Mrs. K. R. Followed by her married name. Most people called her Kath or Kay. Years later when I got her birth certificate, she was Rosie Kathleen.
Carol