
She knows very well that ian was the one helping her in her previous life? This relationship will never fly if she doubts him based on every layman's words. Especially if the person is a known schemer. If she ends up alone it would make more sense, seeing how she trusts no one. Not even with ian, the person who trusted her and helped her every step of the way.

She was hesitant about being in a relationship with iam when he confessed. That is perfectly fine. Here, at this point, after all he has done, not trusting him is a sign of bad, manufactured drama. She has been smart enough over and over again to see through nera's and marianne's other tricks. But all of a sudden she believes marianne's mother's words without any proof? Right..
She knows exactly how scheming and bratty that pout-marianne is. And she knows how much she chased ian recklessly without him ever being interested in her. Why would she believe the words of marianne's mother-spoken in ian's absence- over ian's words? Idiotic.