...she strikes me as far more bitter, far more opportunistic, and far more conniving than he does.

Well, she has the advantage of having been married to Bill for a good number of years. She's had ample opportunity to hone that skill set while observing a true master of the art. She's learned well. I would give her marks equal with Bill's on the conniving and opportunistic fronts, but she actually leaves him in the dirt when it comes to bitterness.