Coming back from the dead is not the easiest for anyone. Not only does Mary have to readjust to life after death, but she is also displaced over 30 years after the time that she knows. Perhaps the worst thing for Mary is everything that she has missed. Her death caused a chain reaction that turned John into a different person and pushed their sons into being soldiers. She is lost in a time that she was never supposed to exist in, which is something that Samantha Smith understood about the character.
"She wasn't just this sort of perfect mother character that they all expected. So I think that was a big adjustment for the boys. They had this canonized version of their mom and she just wasn't that person," Smith told IGN in a retrospective of the character. She went on to say, "And I think that, if anything, it expanded their understanding of what unconditional love of family really is, because in true Winchester fashion, she didn't do what they wanted her to do or what they thought she should do, she did what she thought was right and they had to love her anyway."
Smith brought a real sense of empathy to the character which made her layered and complex. It wasn't the picture of her that her sons remembered, but it was more important. It made her a real person, for better or for worse.
