Well, I don't know what the author considered to be ridicule on Twitter. It's not the case that all ridicule is "cyberbullying". I also note that the other person wasn't directly engaging the author on Twitter (via "@"), since the author acknowledges she only found it be searching for her name.

If I ridicule, say Justin Bieber, on Twitter without directly engaging him, am I "cyberbullying" him?

I don't know the whole story here, but what's been presented certainly is open to being flipped around the other way.