What is the meaning of a feather split down the middle to a Native American Indian?

Menada assigned the man with the split feather the task of protecting the White Buffalo and promised them that when the split feather is joined together, it will be time for her return to accompany them on their journey Home.

https://www.aaanativearts.com/kiowa-apache-white-buffalo-woman-legend
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And then again, it could be less mythic, as in these two examples:
"In his hair he wears a wooden knife to represent the weapon he wrestled from a Cheyenne, the six coloured wooden sticks represent gunshot wounds, the split turkey feather stands for an arrow injury and the others feathers probably represent other feats."

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White Hawk was taken from her family when she was 18 months old. As an adult she finally met a man who was her brother. She said her brother always thought he had a sister. They lived in different parts of the country. What many American Indians want the social system to understand is that the tribal ways are still important and in place. "Our systems are in place. We have come back, our family system is strong," White Hawk said. She called it the "split feather" syndrome.

https://indiancountrytoday.com/archive/split-feather-syndrome-addressed-at-sd-committee-hearing