Barnstable, Mass. ? Eunice Kennedy Shriver, a sister of President John F. Kennedy and a longtime champion for the disabled, was in critical condition Friday at a Massachusetts hospital.

The 88-year-old Shriver’s husband, 1972 vice presidential candidate and former Peace Corps director R. Sargent Shriver, gathered at her side along with their children and grandchildren at Cape Cod Hospital in Barnstable, said family spokesman Stephen Rivers.

California Gov. Arnold Schwarzenegger, the husband of Shriver’s daughter, Maria, was also there, said Aaron McLear, a spokesman for the governor.

Shriver has been weakened in recent years by a series of strokes. She lives in Hyannis Port, near the family compound where her brother, U.S. Sen. Edward Kennedy, has been staying as he undergoes treatment for brain cancer.

Shriver is the fifth of the nine Kennedy children. Edward Kennedy and Jean Kennedy Smith are her sole surviving siblings.

Shriver is perhaps best known for her work to establish the Special Olympics, inspired in part by the struggles of her mentally disabled sister, Rosemary.

She organized the first Special Olympics in 1968 in Chicago.