As I have said before examples in Avatar do source reflect upon real world cultural roots , If one takes a look at the examples of the "Dream hunt" content and what it reflects upon, many of these roots have cultural connections in central and south American native tradition "who call there spiritual healers "shaman" Avatar also reflects upon some the root storys of north American native peoples Who call there spiritual healers "medicine men and Woman" primary difference's , south American shaman use "hallucinogenic plants like "Ayahuasca" to help a person determine "who they really are" in North America , instead of using plants, people usually "Fast" for insights upon deep core issues in there lives (there are some southern native peoples in North America who use peyote) , both shaman and medicine men-woman have a relationship with spirit that is very poorly understood in our cultural world view "Ethos" that dictates "separation" we are separate from plants, and animals and often its seen that plants and animals where placed here to in some way serve "humans" Avatar through its deep reflective symbolgy reflects upon how the Na'vi "See" each other and the world around them much differently then we do, one of the core strengths of Avatar is its story's source roots, there are a number of examples on youtube of experiences of being a shaman's apprentice the problem is sorting through the "authentic" root examples and those that do not present true fact or contain very poor translation of vital important underlying meanings leading to a lot of confusion, it takes a lot patience and study of cultural understanding and history to sort through but can be a very insightful learning experience on many levels if one is willing to put the time and effort into this understanding.
Many internal underlying aspects of Avatar have there roots in living breathing "real world" native peoples , from the Na'vi structure of community oneness , Native community leadership structures, like the role of the clan mother , (reflected in Avatar by Mo'at who is training her daughter "Neytiri" to take on her vital position)
In native American culture it is the women who collectively core see this developing in a young child-adult the signs of the inner drive to help unify and heal the people (He or she Is somehow a little different), and then that person is given the choose to train with the current medicine man-woman to learn to core connect with the world around them, to recognize the healing powers of different medicine plants and develop there inner intuition to help one in need of healing, this comes from the development of root core compassion and there are no "services rendered" like a doctor in our culture, in reality the medicine man or woman helps the person to find and re-connect with there own "source inner insight
so they in actuality are able to "heal themselves", "Medicine work" is for both a persons physical and mental well "being"
so a "medicine" man or woman as well as a shaman must be very broad skill based as apposed to a western doctor, who only treats the body like a "broken biological machine"
In this example that relates to the medicine wheel there are some good examples of the differences of world view and how a person is "seen" in native medicine.
https://www.youtube.com/watch?v=fIGrFHy463g
(this is part one of a three part thread and there are examples in part 2 and 3 that interconnect )
Getting back on focus on the world of "Avatar" there does appear in the Na'vi community structure a family connection between Mother Mo'at (current Tsahik) and Daughter "Neytiri" (Future Tsahik) so in Cameron's constructed Na'Vi world "ethos" family ancestry linage likely plays a large role in who stands in her position , only Cameron can truly answer your question, I can say in studying South American native peoples , its not at all uncommon for a Shaman to pass down to his son or daughter there skills and position but there is a very real risk today to loose the knowledge if it is not passed down due viewpoints of other cultures (Often imposed by religious teachings) that decimate oral tradition of passing down these skills from elder to young adult.
