The funeral of Dolours Price, who was jailed for her part in the IRA bombing of the Old Bailey courthouse in March 1973, has taken place at St Agnes' Church in Andersonstown in west Belfast.
The 61-year-old, who was originally from Belfast, was found dead at her home in Malahide in Dublin on Wednesday night.
Her death is not being treated as suspicious.
Her sister, Marian, who is in prison accused of dissident republican activity, was not at the funeral, although she was allowed to attend the wake at the family home yesterday.
In recent months, Ms Price gave a number of press interviews in which she claimed she drove Belfast mother-of-ten Jean McConville to the place where she was murdered by the IRA.
Ms Price also alleged that, during the early 1970s, Sinn Féin leader Gerry Adams was her IRA "OC", or commanding officer.
She alleged that he had personally ordered the abduction of several people the IRA considered to be traitors.
Mr Adams has always denied being a member of the IRA.
Yesterday, he said he was saddened by her death and felt a deep sense of solidarity with her family.
Ms Price, the former wife of actor Stephen Rea, was convicted and jailed along with her sister for the 1973 car bomb attack of the Old Bailey in which one man died and more than 200 people were injured.
She spent eight years in jail, including several weeks on hunger strike, before being released in 1980.
Her sons Danny and Oscar and her sister Clare were among the mourners at the requiem mass.
A number of women, who served prison sentences with the Price sisters in England and later in Armagh, took turns to carry the coffin on the route from the church to Milltown Cemetery.
They included the Co Donegal-born Gillespie sisters, Ann and Eileen.
Colin Duffy, a former IRA member who last year was acquitted of charges linked to the murder of two British soliders, was also among the mourners.
The graveside orations were delivered by Eamonn McCann and Bernadette McAliskey.