The review distribution in her GoodReads profile doesn't look like that of a troll or griefer. I thought it'd be bimodal with a huge number of one-stars. Instead it's unimodal centered at 4/5. Just like a book enthusiast who likes most of the books she reads.
Her Twitter and GoodReads profile are private now, but from what I can tell from the Guardian comments from people who did read them she isn't a troll - she genuinely didn't like the book and really did think that some of the sex in it was rape, by virtue of one of the parties being underage and so unable to give meaningul consent.
Imagine a slightly different version of this story, told from the other viewpoint:
A woman writes a negative review of a book that she feel trivializes underage rape and PTSD. She encourages others to see the book in that same light.
She hasn't used her real identity online, and she's sensitive about rape and trauma. Is she hiding her ID for reasons of safety?
The author then net stalks her, finding out her where she lives and where she works. The author calls her (more than once!) at work, saying she knows who she really is. The author also drives to her home, but doesn't knock and leaves a book with the creepy title A Short Guide To A Happy Life (is it a hidden message? SHORT LIFE?) on the doorstep.
Then the author publishes her real name in a major newspaper, resulting in views all over the planet. Whatever reason she had for keeping a low profile, even if it was for her own safety from a past abuser, it's blown now.
The story sure looks different from that angle. Not saying it's all the way things are, but it's certainly a valid alternate view.
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.