After watching the fast-paced regeneration of the student, Silver pretty much confirmed her suspicions. The student that was known as Peter was a Wight. There weren't many things out there with such a fast healing speed. The only other thing that had a similar healing speed was wendigos but it was clear that Peter had kept most of his human appearance, so it ruled that possibility out.
Now that there weren't as many fights going on, she could also concentrate and found that there was no heartbeat. All these things led to the conclusion that he was a Wight.
'This could be a little troublesome or fairly easy to deal with.' If the Wight was created by Fex, then it would be impossible for her or him to kill it and she would have to find some other way to get rid of it. There was no way she could leave now knowing what was out and about, without a ladder they could quickly go out of control.
If it wasn't created by Fex, then that could be even worse.