(CNN) - Relatives of Eunice Kennedy Shriver were summoned to a hospital on Cape Cod, Massachusetts Monday, a source close to the family told CNN.
"It's minute-to-minute right now," the source said.
Shriver, 88, has been was in the hospital for several days, her family said, and her relatives were summoned after she suffered a "setback," the source said.
Shriver founded Special Olympics. She is the sister of former President John F. Kennedy.