Katherine Schwarzenegger has paid a birthday tribute to her father Arnold Schwarzenegger with a series of childhood images. The ‘Terminator’ legend turned 75 on Saturday (30.07.22) posted a variety of poignant snaps in an Instagram post, including one of the pair riding horses as Arnie makes a peace sign behind her head. Katherine captioned the post: “Happy birthday daddy!! We love you so much! “You’re the best and most fun opa and dad and we are all so lucky to have you in our lives! Happy happy!!” The author – the daughter of Arnie and his former wife Maria Shriver – is married to Hollywood …