I get a strong sense that Bella is an IxFP...
She seems very lost in her own inner emotional world a lot of the time oblivious to her friends. When Edward (in the film btw) starts staring at her, it's like she suddenly enters this intense emotional inner world wondering about him and what he feels about her and how she feels about him which seems very Fi-Dom to me.
Also she seems someone who is a bit more laid back in decision and plan making typically going with the flow and thinking on her feet hence the P.
Don't know whether she is N or S but most likely INFP imo as as soon as she learns about Edward and his family's weirdness she becomes very interested in them, brainstorming what he could be hiding/why he acts so strange which is more of an N thing.
No idea what Edward is def. Ixxx though
Jacob - ESFJ (as he is Fe-Dom would explain how he gets on with Bella so well as she is Fi-Dom)
Alice - ENFP