To those who say that Bella is a spine-less coward:
Show me where. You're going to have to give me page numbers 'cause I'm not seeing it. I do see however a girl with extreme confidence in herself who pursues what she wants despite everything her family and friends tell her and who, while experiencing fear like any other normal human being whose life is in danger, presses on regardless. You want examples? I'll give you examples.
Twilight - Bella decides to move to Forks so her mother can have a life she wants with her husband; she goes to the ballet studio all alone to meet a vampire who can kill her with a flick of a finger because she thinks she can save her mother; she maintains that she wants to be with Edward even though he clearly doesn't think it's a good idea for her.
New Moon - she faces Jacob when he begins avoiding her; when Alice tells her Edward is in trouble she does not hesitate, she is ready to go to Voltera on a moment's notice to protect him, even if it means risking her own life; she goes to the Cullens and asks for a vote on her humanity and becoming part of the family; she defies both Jacob and her father by staying with Edward.
Eclipse - she maintains her friendship with Jacob despite Edward being against it; she continues her relationship with Edward even though her father and Jake would clearly rather she didn't; she wants to go to the face-off with the newborns and doesn't only because Edward won't have it; she risks herself during the Edward vs. Victoria fight.
Breaking Dawn - she joins forces with Rosalie of all people to protect the child she wants to keep; she goes alone to establish an escape route for her daughter and Jacob and protect the secret from the Volturi.
To those who are outraged by these books spitting in the face of feminism by portraying a heroine who "can't stand on her own and always needs a man" and is accepting of a guy who'll disable her car so she wouldn't be able to go see her friend:
We all look for love. We all look for a mate, a soul mate if we're lucky, and there's absolutely nothing wrong with looking for that and hanging on with all your might when you find it and know without a shadow of a doubt that this is it. Bella is female, a heterosexual one, so yes, she looks for the mate among the opposite sex. That is still the prevalent tendency in any society, last time I checked.
Now, let me ask all you "feminists" who are crossing your arms and digging in your heels right now. Have you ever had your heart broken? Was that person the one and did that breakup crush all your hopes and dreams in one swoop? If you answered yes, remember it. Remember the pain and how the days seemed grey regardless of what the sky looked like and there was no more happiness in the world to be found anywhere. Never felt that? May be you haven't loved that much. (Hold the screaming until I find my earmuffs, please. Ok, got 'em. Go ahead, let it loose.) If you loved and felt and remember - is it really that unreasonable for Bella to be heartbroken? I don't think so. In fact I think if she just shook it off and moved on I would've been disappointed.
On to the "unhealthily controlling boyfriend" part. On one hand, granted, it can be perceived as creepy and can call for a break up and a restraining order. On the other hand we're not dealing with any kind of usual situation here. There's real danger there. As in life and death. So yes, I think extreme measures are warranted. Oh, I can hear the screamers "But she's letting him get away with it! Unhealthy patterns!! Red flags!!!" Yes, she's letting him get away with it. I wondered why myself and decided that the reason is that finally someone is taking care of her, as opposed to her taking care of everything and everyone and making sure people have food in the fridge and their driver's licenses don't expire. She grew up being the responsible one, now Edward, the Cullens and Jake are taking care of her and I imagine it felt good for someone else to be in charge for a change. She could relax and not have to be in control of everything any more.
We all want to be taken care of and if you believe otherwise you're just kidding yourself. Deep down inside we all want to curl up on the couch once in a while and not have to worry about anything other than our own ideas and selves. For most of us that's what we get during our childhood. Bella had no childhood and this is her second chance at it. Besides, it's easy to forget, but at 17 she's still a kid. She needs someone to look after her and she's found that someone in Edward. For that, among other things, she'll let it slide.
I know I'm talking about fictional characters as if they're real people. Contrary to popular belief not all Twilighters have trouble differentiating between fiction and real life. (I read the other day that people come to Forks, WA and ask if it's ok to go hiking considering the vampire situation. Really?) My theory is that in every work of fiction there's a little bit of fairy-tale, the rest is all true and it takes talent to merge the fantastical features with the truth to make them into one tale, solid and seemingly real. To me books with relationships that don't resemble day-time soaps are case studies in human behaviour, with names changed for privacy reasons and settings altered almost beyond recognition, but the core of it all is still there. There's a Bella in all of us, just like there's an Edward and a Jake and a Rose... you get my point.