Yeah, I think that's just a misdirection. At this point I am certain that the third claimant is Bella, even if it's a bit on the nose. The whole game is littered with subtle and not so subtle references to Bella being the third claimant.
I know some people say that it's so obvious that it can't be her, but I disagree. Big reveals don't always have to make you go "Holy Shit! I did not see that coming", sometimes they can just be "Hmm. In hindsight this makes perfect sense". I'd say that's a whole lot better than having your "expectations subverted".
Also, the gold digger (the one who knows the conditions of all 3 claimants and sent the email to Monica) can not be anyone other than either Bella or Elaine because...