Trusting a well intentioned "stranger " that you've lived with for over 7 months is apparently an idiotic move but wanting to marry the tormentor of the one who you apparently love so deeply, whose vileness you've experienced first hand and have warned your spouse to stay away from, is completely alright. That person who was scheming to get hold of your hospital by using your brother as a crutch 4 days before he died, suddenly turned into an angel in your eyes just because of his death. She also could've turned out be the manipulative opportunist that she is, who was only faking her grief or pregnancy or both.