@Stack
In a legal sense, she was indeed a victim of what Johnson did. But in my opinion - based on the Whatsapp messages and other bits of evidence, I believe that the victim here was aware of the situation and knew what she was doing/getting into, just as well as if she were a year older (and therefore of legal age to consent.)
Legally, the victim is indeed not able to make a sound judgement or decision in instances such as these, but this does not inherently make the experience traumatic for her.
I think we can boil this down to a couple of fairly straightforward questions;
1) Do you feel that Johnson's actions directly caused the victim a significant amount of pain or hurt?
2) Do you think the victim would have been better off if this entire incident had never made it to the media and public eye?
My answers are 'no' to question one and 'yes' to question two. None of this is an attempt to absolve Johnson of any blame, but rather I am thinking purely about the victim's situation here. It raises a potentially interesting legal/moral discussion in itself in that if (hypothetically) there was a choice between protecting the victim and punishing the offender, which do you/should you pursue?