John Singleton's mother is holding her own in a fierce family battle for control of his estate -- as he lies in a coma -- and it's all about who gets access to what, and most importantly ... when. Also, Arnold's having a crazy busy weekend ... he was a proud papa Saturday morning at his son, Joseph Baena's college graduation in Malibu. His daughter Katherine Schwarzenegger enjoyed the company of a very special guest at her huge blowout bridal shower ... Oprah!!!