I'm sorry, but no, she is not a bitch. She was as loving and supportive as she could be under the circumstances. Andy was completely self-centered throughout the movie, and only in hindsight does he ever realize at any time that he has been so, finally apologizing ONCE for the things he's done.
First, he makes her move out to the country so that he can write a novel, likely regardless of her feelings on the issue, and instead of fighting with him about it, she tries to make the best of the situation and supports him. Second, he tries to force her to go to town, when she expressed no interest in doing so, but again, she does it to support him because he wants to go to town. Third, she finds a corpse in the garden which would have sent anyone else running (and yes, she did say she wanted to move at that point), but she stays once Andy has it removed, and even continues to stay when he loses it and has the corpse brought back and re-planted. Fourth, she gets an idea to write a story herself. No, she didn't tell him about it until afterward, but frankly, I wouldn't either. Why? Because like her, I wouldn't have wanted to jinx anything, nor would I want to get my or anyone else's hopes up in case nothing comes of it. When something did come of it, she didn't hide it, she went to him and told him, hoping he'd support her as she had been supporting him, but that didn't happen. It wasn't until she told him that it was a children's book that he relaxed and stopped feeling jealous.
Throughout the movie, time and again, she is supportive of him while he is repeatedly selfish and thoughtless. And as to her "rushing" to get a divorce? He pushed her to it, and if you listen carefully when she's yelling at him about stealing her story and passing it off as his, she lists numerous things he's done in the past, not just since they had moved to the country, but things he'd been apparently doing for YEARS, but the final straw for her was the stealing of her story. Pretty understandable to me.
As for her "ripping his novel to shreds?" Really? It was an extremely inappropriate time to ask her to read it, and seriously, what was she supposed to do, lie? He forced her to read the beginning of the story, and then demanded her opinion. So she gave it to him. She told him what she thought and why (and if it really was because of flashbacks and such, then that is totally understandable. I've read many, many books, and if they've had flashbacks, and the flashbacks weren't done clearly, it does get confusing to the reader). It was confusing to her, and wasn't an interesting story to her.
Now, I understand his reaction. For someone trying to write, they pour their heart and soul into their story, and hope that people will like it, and so it's hard to take the criticism. When I write things, I still sometimes have to walk away for a while if someone gives me criticism, even if it's constructive. It hurts, but that's why I walk away, and give it some time. I then usually see that what the person has said is correct, and why, and I look into making corrections, and if I disagree with what they've said, I make the decision to leave things as they are. But that didn't happen here. They got into a fight about it because he wasn't expecting her reaction, and he should have walked away to process what she said, but he didn't. He made a knee-jerk reaction to what she'd said. And when time did pass, and he did think about it, he came back and apologized.
So, no, she wasn't a bitch, especially considering everything she had been putting up with from him for years in the city, and now in the country. Frankly, if it had been me, I would have lost it long before she did.
EMOTICONS ARE BACK! YAY!