Because she is equally guilty of poor judgment. There's no law against making poor decisions but there are potential consequences.
If I step off the curb into traffic and get hit by a car I'm the victim because by law the pedestrian always has the right of way. But I am nevertheless guilty of poor judgment and the consequences of that poor judgment are mine to bear even though I am still technically the victim.
This has nothing to do with shaming. It's a simple acknowledgement of the fact that her poor judgment played a role. She isn't some innocent waif, in fact she's older than he is. For his part he apologized publicly, paid the fine and offered to remove himself from the entry draft (even thought was never his decision to make). Does he also have to wear a hair shirt and flagellate himself to satisfy the mob? Who decides when he's finally suffered enough and paid his penance? Craig Button? Eric Engels?
What more of this kid is required exactly? Because I don't recall this level of outrage back when Patrick Kane or Auston Matthews acted like idiots and both of them were older than this kid.