Yup, that is her flaw and her sin, that is what got her body in it's present shape to begin with. She took pride in her judgement verses that of the Almighty, got not only a Sword broken but her body as well.
A good Viking warrior wouldn't do stupid.. Her present course is stupid.. Harry knows, he also knows he cannot stop her, he also knows how it will end..
Perhaps she knows how she wants to go out?
A lot of people who have been fighting a long time, including people I served with, would much rather go out feet first. When you have been in the life long enough it sort of limits your options in ways people who have never been there cannot understand.
Fighting is what she knows. She fought to protect Chicago - her home. She fights to protect Harry. Murphy fights to protect what she loves and is willing to risk or even sacrifice her life to do so.
No greater love . . .