Madge's grandmother Elsie Mae Fortin died yesterday in Bay City, Michigan.
It has been believed the 52-year-old singer was partially raised by Fortin when her own mother died in 1963 from breast cancer - Madonna was just five years old at the time.
Just before the star was inducted into the Rock and Roll Hall of Fame in 2008, Elsie told her local paper, the Bay City Times: 'She has done things that I didn't approve of, but at the same time she's my granddaughter and I still love her and I am proud of her hard work... She has been good to me.'
The Queen of Pop's publicist said in a statement: 'I am sorry, but Madonna will not be issuing any statements or conversing with the media regarding her grandmother. It is a totally personal matter to her.'