Yeyu means mom in Kryptonian! At least in most fanfics on this topic you will find children calling Kara, Yeyu or Jeju, the truth is I'm not sure which of the two is correct. If you want you can read about it here: www.tumblr.com/kuekyuuq/655816033331986432/a-little-lesson-in-kryptonian?source=share