I know we are bored and all but lets stop with crazy Bella theory
Ooh, are we doing Bella theories? Because I've got one:
James never left her; he's in that locked room, in a coma, on life support.
When she says to his picture, "I've forgiven you, please come back to me," "come back to me" = "come out of the coma." Why does her forgiving him matter? Because whatever argument she's forgiving him for is what led to him being in a coma. They fought, he stormed out and drove off to clear his head, but instead ended up driving like an idiot and got in a wreck, which ended up with him in a coma.
That's why she cries when MC kisses her in the library; not because she feels like an adulteress for cheating on a husband who bailed on her three years ago, but because she's finally starting to accept that he's gone for real and he's not coming out of the coma, and she's grieving.