Phoenix is the woman reborn--just like the mythical bird, a phoenix, dies and rises again in the ashes, the grandmother reinvents herself every time she has to make that trip. She is strong enough to do the job although she doesn't appear to be.
The hunter represents prejudice and racism. Take a look at his language in the story and it's not hard to see why. Phoenix has dealt with his kind her entire life.
I wouldn't say any of these characters are dynamic except for Phoenix herself. She is the only one who actually rises off the page to become real and palpable. The others don't change, they are just there to move the story along. Phoenix is three-dimensional and alive.