Although of course this is uncited information from Wikipedia, the Kyoko section of Yoko's page says "In 1994 (some sources say 1998), Kyoko, fully grown and married, re-established a connection with her mother that resulted in a 2001 reunion. Kyoko's daughter Emi also met her grandmother at this time. Although Kyoko avoids publicity, she did grant an interview where she revealed that her reunion with Ono was a very happy one, and they remain in close contact to this day. Kyoko made a rare public appearance in August 2005 at the opening of Lennon, the Musical."
I'll leave this up to you guys to determine whether this is true. I wouldn't know where to look to verify that information.