Well, shunning for life would be one way to demonstrate she's irredeemable.  In Jesus day, there was a distinct caste system, with certain people considered worthless.  Nothing they could do would make them right with God, according to some Jewish leaders.  The Samaritans fell in this category, due to intermarriage.  Not enough room here to go into detail.  But that fact makes the story of the good Samaritan even more profound. 

Treating someone as irredeemable could include shunning, or just viewing them as garbage and worse than you are.  Calling this girl "immoral" instead of saying she had immoral behavior is, IMO, judgmental.  The social media harassment is definitely judgmental.  Attacking & condemning a person, rather than actions, & treating as if God doesn't love them is judgmental.  Jesus wanted us to look at every person as someone that God created in His image & loves, & as someone Jesus died to save from eternal punishment.  Killing is a topic for another post.