Her reasons are that he is short and she thinks I'm choosing bad genetics for my future kids. (Though he is a couple inches taller than me). She says she knows he's a good person but doesn't want me marrying him. She also thinks he is unattractive and so that adds to the bad genetics. Basically, she thinks I'm settling, but she also has anxiety and depression and it has become the hardest situation she's been through in her life (is what she said).
With this situation I've also looked back on my life and seen that she's supportive of me if I do what she wants. I've always tried to make her happy.