She probably could get more help from someone who's an expert in computers and especially the internet. A hacker type probably would have better success at tracking the culprit than the cops would. It's actually easier than people think. You just need to know how it's done.
Years ago i suspected someone was impersonating me and sending emails to 'ladies' i had befriended. My email address would even show up as the sender in the various emails they'd receive. And of they'd reply to a particular email, the culprit's account would receive their reply. Not mine, the one that was on the email's header. I only found out about this scam when one of the 'ladies' confided about 'my' emails to an acquaintance of mine. She showed him the email. When he told me about this i had no idea what he was referring to and realized someone had been impersonating me simply to cause trouble.
So i asked a friend of mine to look into it and he was able to hack into the culprit's account. He also showed and educated me onto how easy this scam could be done. I tested it on myself and to my great surprise it worked. It was so easy to accomplish that it was downright scary! I told my friend: "If they don't believe me that i've been victim of a scam, i'm fucked!" He replied "Indeed, you're literally fucked since i don't believe someone who isn't computer or internet savvy will believe your story. And if someone savvy enough and willing to put in the effort, they can virtually fuck anyone they want."