Possible Clues:

• Julian's stepmom
• ''The Ballad of John and __''
• Name whose Japanese symbols mean "ocean child"
• John's other half
• "Give Peace a Chance" collaborator, with 6-Down
• See 43-Across
• Ono, Mrs Lennon
• John Lennon's wife Ono
• With 116-Down, "Bed-In for Peace" co-organizer
• John's widow