Continuity mistake: When Tristan returns to see Suzanne at her new home with Alfred, her hair is down. But in every shot her hair is either pulled behind her ear, then both sides in her face, then one side pulled back, and so on. (01:25:55)
Visible crew/equipment: In the opening scene, when the COL is sitting in front of the cabin, a modern pickup or van can be seen in the background.
Continuity mistake: When Susannah finds Tristan crying at Samuel's grave she takes him into her arms and consoles him. This is seen from different angles, with Tristan's hair behind his ear or not, and in one strange brief shot with a straight, expressionless face, very different from all others where he is sobbing hard and his face is twisted with grief. (00:53:25)
Audio problem: When Tristan returns the second time he is driving horses along, shouting loudly, but without moving his mouth. (01:19:35)
Continuity mistake: When Susannah comes to the ranch she takes a photograph of the three brothers. Alfred is holding a glass and has both legs up. At the end of the movie Tristan looks at the picture, and Alfred's glass is missing, and one leg is stretched out. (01:54:00)
Continuity mistake: When the second German cavalryman attacks Tristan he is aiming his rifle at him. When he gets shot down he is holding on to the reins, and the rifle is gone. (00:39:40)
Continuity mistake: When Tristan and Samuel talk about premarital sex, some strands on Tristan's right temple hang down or are tucked behind his ear alternatingly. (00:20:30)
Revealing mistake: When Tristan takes revenge for his brother and scalps two German soldiers you can see that his knife just goes through the hair. (00:44:25)
Continuity mistake: When Tristan and Samuel hug in the trenches in the war, at first Tristan's chin is on top of Samuel's hat, but when it cuts to the other angle, their heads are level, side by side. (00:36:00)
Continuity mistake: In the scene of Alfred and Tristan at Susanna's grave, when shots of Alfred show him speaking to Tristan, he looks to his right, as if the two men were side by side and facing the grave, and they seem to have been side by side in the last shot in that scene, when they leave the grave-site. However, the sun lights the left side of Alfred's face, and in the alternating shots, which show Tristan listening to Alfred, the sunlight is on the right side of Tristan's face.
Answer: Cutting locks of hair is often done in memory of the deceased. Knowing of her impending death, she cut two locks so as not to have them tainted by blood, but dropped one on the floor. I imagine it was the one for Alfred, but it is just my opinion.
I have goosebumps with this interpretation. I always thought that it was related someone with "scalping." She kills herself. She is her own victim. I don't know.