The author describes Miyax's appearance directly four pages into the book.  She says,

"Miyax was a classic Eskimo beauty, small of bone and delicately wired with strong muscles.  Her face was pearl-round and her nose was flat.  Her black eyes, which slanted gracefully, were moist and sparkling...she was slightly short-limbed".

To describe Miyax's personality, the author uses a different method.  Instead of telling us what she was like, the author shows us through Miyax's actions.  We can tell that Miyax is patiently observant and intelligent in the quick way she learns and remembers, and we also know that she is resourceful and self-reliant.  All of these traits are evident in the way Miyax seeks to survive with the wolves, intuitively using the concepts her father has taught her when she has to survive on her own.  Miyax is also pensive and has a deep affinity for nature, struggling to reconcile encroaching modernity and civilization with the old Eskimo ways she has been taught.  In evaluating and prioritizing her values in a changing world, Miyax shows a depth of character and a precocious maturity.