Signifiance/symbolism of Suzanna cutting her hair?

An act of defiance (symbolically scalping herself) and taking back control.

Susannah felt she had no control over her life, over who she loved, over her desire but ultimate inability to have children. She was lashing out, rebeling, so to speak before taking her life...sort of as a FU to the universe.

That's my take on it anyway.

Susannah made her choices. She chose Samuel and filled his head with idealism regarding the war, she lusted after Tristan, she took advantage of the father's hospitality, and used Alfred. Thank goodness she didn't have children.

Cutting her hair was acting out on her part. She was unhappy with her life. It was symbolic for the film. It was her kill so her scalping.

Remember the narration during One Stab's actions over those lying dead which came to kill Tristan.

I think she cut her hair so that she couldnt back out from killing herself