Romilde Trapattoni (83) died last week after a long illness in the Milan convent where she had spent most of her life after taking her vows as a Sister of Charity.
Trapattoni walked behind the hearse carrying her coffin to the church at Maggianico for the funeral Mass, which was private. The remains were taken back to Cusano Milanino for burial.
The Irish team manager was very close to his sister, who sent him bottles of holy water which he would sprinkle on the pitch during big games.
Romilde entered the St Maria Bambina Convent in Milan when she was 20.
Father Paolo Ventura, who officiated at he service, said yesterday: ''Sister Romilde was a wonderful person who was well liked by all her fellow sisters.''