By leaving Monica and the sisters behind... There is no requirement (IIRC) to leave everyone behind. So Elaine could easily be deciding to try and drive the MC away from Monica so he takes all of the money AND falls for Elaine (once a gold digger always a gold digger)I think only the MC can get all the money by leaving this mess behind, I think both the others have conditions tied to the MC one way or another.
And I think you will be eating those words at the end... Just don't see her as trustworthy at all.And Elaine is a sweetheart, you'll see.