Continuity mistake: The headstone on Samuel's "heart grave" had writing in the cross bar ("We will not see him, but we shall join him"), as well as his name below followed by "born" and "died" dates. The next three times the grave marker was shown (from a distance), only "Samuel Ludlow" could be seen etched on it. (00:49:47 - 00:54:54)
Factual error: The three Ludlow sons were leaving for England on October 14, 1914. When they were walking outside guiding their horses, the small trees in front of the house had green leaves. In Montana, Fall foliage typically begins by early - or mid-September. In most of the state, there should be peak Fall foliage (yellow/orange/red leaves) by early - to mid-October, not green leaves on the trees. Also, some time later when the sons were riding their horses through the field, the leaves were still green. (00:28:21 - 00:32:00)
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.
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.