I've collected some screenshots of critical facts dealing with the will.
FYI - I used the incest patch for the game so if the text says "Mom" it is Monica and "sisters" is Katie and Jenna. I know the incest patch isn't popular among the fans here so you don't need to mention that fact, I already know.
Will
The story certainly wants us to believe that Theresa is the religious nut and possibly Dizzy (I'm not saying she is for sure so don't quote me as saying so). The person being dishonest with the player could be Elaine or someone else. Based on all the evidence it suggests that Elaine may be the person who knows everyone's will conditions. Elaine hired her own private attorney and has been very busy trying to ensure parts of the will fall to her favor. She may even be attempting to bypass parts of the will somehow with going back and forth between her private attorney and the MC's dads attorney asking lots of questions.
I'm still unsure how Bella fits into the will, if at all. We know that Elaine suspects Bella's snooping and is considering kicking her out of the house because of it.
It was also very interesting that Elaine went from being extremely rude and heartless to the MC to being all kind and wanting the MC back into her life. If I remember correctly, she even invited him to come back and live there (I couldn't find the screenshot for it quickly).
It is also interesting that it is mentioned several times that your actions affect one of the recipients more than their actions do.
In screenshot 'Will 4.jpg' the MC says that he learned the Bible from a nanny that his father hired to keep him out of his hair and that she (the nanny) was a real religious nut. Could this be Theresa and she doesn't remember him or someone else? We know for sure that Theresa is a religious nut, but is she the only one? From the story so far, she is the only one that has been clearly reveiled as being a religious nut.
It will be interesting to see how it all unfolds!
NOTE: All of the above is my opinion. If you disagree then great. I don't proclaim myself to be an expert here. Have fun and enjoy!