And the film portrays pilate's wife as having attended the gathering of the jews when Jesus spoke to the massive crowds. Do you think this is just thrown in for plot?
No, I don't think such a scene would've been "just thrown in" without awareness of the longstanding portrayal of Pilate's wife as sympathetic to Jesus, as is the case in Matthew 27:19
and in the apocryphal Gospel of Nicodemus
Besides King of Kings, Mel Gibson's The Passion of the Christ shows Pilate's wife acting in sympathy with Jesus by bringing Mary some cloths to clean Jesus' blood off the ground. I'm sure there many other similar characterizations of Pilate's wife.