It's first important to mention the exact moment that Miyax is accepted into the tribe: when she pats the leader, Amaroq, under the chin because "as his eyes softened, ... Miyax was one of the pack." The key to this answer is actually found within something Miyax says after she is accepted by Amaroq:
Wolves are shy, Kapugen had said, and they desert their dens if discovered by man; yet this pack had not. Did Amaroq not know she was human? Perhaps not; she had never walked in his presence, the two-legged signal of "man" to wild animals. ... She concluded that Amaroq tolerated her because she was young, had no gun, and was sad--a lost child.
In short, Amaroq is the leader of the pack, but it is obvious here that Amaroq is not following normal "wolfish" behavior. This is bound to cause issues and different opinions among the pack. This is certainly the case. It should be noted, however, that the impact on the pups is non-existent. Why? They accepted Miyax even before she was accepted by Amaroq. They were already playing/roughhousing with Miyax before she patted Amaroq under the chin.
Another key is that "in order to be fed by wolves one had to be helpless." Once Amaroq gave Miyax the soft-eyed symbol of acceptance, the entire pack warmed up to her easily. Even Nails and Silver think nothing of Miyax joining them in their den. The pack has accepted her! Well, almost the entire pack, that is.
Acceptance isn't so easy for the outsider named Jello, but he is happy when Miyax shows more submission than he who enjoys "acting like the boss" even though he most certainly is not. When Miyax tries to assert her own authority, Jello refuses to regurgitate and feed her. It is the pup, Kapu, who gets Jello to do this. This episode then is the perfect example of rejection (by Jello) and acceptance (by Kapu). And Jello will continue to reject Miyax until the bitter end.
In the book Julie of the Wolves Julie has been by herself in the Alaskan woods. She is hungry and tired. She is lost in the woods and finds herself watching a wolf pack. When Amoraq sees her, he growls and snarls at her. She lays back on the ground in submission and he wags his tail and walks off.
The wolves do not fear Miyax because she is a child and she is non-threatening. She tries to remember the things that her father had taught her about wolves. She respects their territory and is submissive around them when necessary. The pups are the first to accept her and kiss on her.
It takes her longer to get Amoraq to warm up to her, but she eventually gets his affection by rubbing him under the chin. The wolves begin to accept her. Amoraq guides her to their den and instructs her to sleep using his wolf skills. She crawls on all fours around him at first. As the wolves become more acclimated to her, they accept her walking around on two legs. She is a part of the pack.