Isn't it enough that bella suffers a lot??? after edward left her she became catatonic and somehow lose track of time even charlie told alice that she's not acting normal even if jacob is already there, not like someone left her, but like someone died. bella considered that edward is really not coming back not because she doesn't have faith in him but because she loved him so much that she trusted and believed whatever edward have told her.

In my opinion bella did not actually betray edward because all the times that she's with jacob all she thinks about is edward and instead of shutting him out of her life in order to move on bella choses to chased her auditory hallucinations of edward just to keep her hopes alive that somehow he still cares and he did exists. remember edward took everything that could remind bella of their existence. she's totally lost.

I think people should not blame bella for developing some feelings for jacob 'cause the person who's responsible for this is edward, if it wasn't for him bella and jacob's almost love affair is not possible. i know that edward only wanted bella to have a chance at a normal, happy, human life and he's just protecting her. he thought that since bella is human she is capable of moving on with her life and time heals all the wounds but if he is smart enough he should also take into consideration that not all human can easily move forward espacially if they're suffering from major depression. there are some people who could not cope up and sometimes suffers from temporary insanity or worse psychosis. he should have listen to alice's warning.