That was Rosemary.
Kathleen died in a plane crash in 1948, somewhat out of favour with the Kennedys, as she had married into the aristocratic Cavendish family, which was Anglican, conservative in politics, and English - hence no use in Boston politics.
Thanks for the clarification, never could keep the Kennedy’s straight. hahaaha, I remember waaaaaaay back in 1960, high school, giving a talk on why Robt Kennedy COULD be elected POTUS. Funny thing is, no one else knew the difference between “Bobby” and “Jack,” either.