Oscar Pistorius' grandmother Joyce Bekker died at the age of 93 this morning."Everybody is devastated," a source close to the Pistorius family said.Oscar, who is currently serving time for the murder of his girlfriend Reeva Steenkamp, has been informed of his grandmother's death.Joyce, who was his maternal grandmother, died of old-age related complicationsOscar, his older brother Carl and younger sister Aimée, had such wonderful role models in their lives, the family insider told YOU. There was their own mother Sheila, who they never speak of with anything but love, says the source. Sheila and their father, Henke Pistorius, divorced when Oscar was six years old. Sheila died nine years later when she was misdiagnosed with hepatitis.Then there was their grandmother on the father's side, Gerti Pistorius or Oumi, as they called her, who died at the age of 92 at the end of last year.Granny Joyce was born in England. She met her husband, Leonard Arnoldus Bekker in Kenya, where Sheila was born later. The family then immigrated to South Africa. Leonard Arnoldus died at the age of 90 about five years ago.Joyce has lived in Bryanston, Johannesburg, for the past few years.According to the source, Joyce, like their mother and other grandmother Gerti, was a rock for Carl, Oscar and Aimée over the years."They are so blessed to have had such beautiful, strong ladies in their lives."Their mother was a strong lady with so much love, so much grace and strength."Their grandmother was the same. Grandma Joyce was a remarkable woman. She had a great sense of humour with a toughness in her as well as a resilience.”Oscar, Carl and Aimée’s only surviving grandparent is their grandfather Hendrik Pistorius, who will be 100 years old at the end of the month.