There had been some question whether or not Caroline Kennedy and Sydney Lawford had entered their cousin David Kennedy's hotel room about 90 minutes before his body was discovered. The Boston Globe reported yesterday that the Palm Beach, Fla., chief of police says there is no evidence to support that contention . . . Prince Harry will be christened four days before Christmas. Little Hank will have six godparents, but oil magnate Armand Hammer, who was said to be in the running, is not on the list . . . Miss Venezuela, 21-year-old Astrid Herrera Irazabal, won the 1984 Miss World title last night in London . . . Even presidents can get put on hold. President Reagan decided to call Russell McCuen, a terminally ill teen-ager, earlier this week in his Houston hospital bed. But while they were talking, his aunt called, and he put the president on hold for a few minutes . . . National Symphony Director Mstislav Rostropovich was invested yesterday in London as a fellow of the Royal College of Music by the Queen Mother . . . Rock star Prince will be donating 100 tickets for each of his seven shows here to benefit the Westside Preparatory School in Chicago run by Marva Collins. And Prince is giving away the good seats that sell for $50 each . . . Maybe it means something -- The Globe Bookstore on Pennsylvania Avenue, conspiciously close to the White House, reports it's having a hot run on books about Nicaragua . . .