How does Kira evolve in Lois Lowry's Gathering Blue?

I think Kira changes so much throughout the novel because of two reasons.  

First, she has to change and adapt in order to survive. The culture that Kira lives in does not take kindly to people that cannot contribute to the wellbeing of the village. Babies that are born crippled are taken out into a field and left to die. People who are injured and unable to work are left out to die. Kira knows this. She should have been killed as a baby, because her leg is crippled a bit. Her mother is quite influential in the village and was able to keep Kira alive, but after Kira's mom dies, that protection isn't there anymore. Kira must adapt and change in order to survive. 

The other reason that I think Kira changes so much is because of what she learns throughout the novel. She learns from her mother. She learns from her friends. But her education is most drastically affected after her mother dies. At that point she becomes a ward of the state and must live in the Council Edifice. It's there that she learns specifics about the superstitions of the village people and how to overcome her own fears. As she gains more understanding of the world around her, she can't help but be changed.  

How does Kira's attitude toward the fen people change in Lois Lowry's Gathering Blue?

In the novel Gathering Blue by Lois Lowry, Kira's attitude towards the people in the fen changes when Matt becomes her friend.  Matt, even though he is dirty, abused and neglected, is free to move about the village staying out of sight.  He helps Kira understand that even though she is privileged because she has special talents as a weaver, she is a prisoner.  When Kira sees the chains on the Singer's feet, she truly understands that she is not free.  Matt is free, has been all over the village and beyond into the forbidden spaces, and tells Kira that there is a village in the forbidden space.  She meets her father whom she thought dead.  Kira now understands that the people of the fen may be dirty and looked down upon, but they are much more free than she is.  For her, Matt is the symbol of the freedom of the fen.  Even though Kira decides to stay in her own village, she doesn't forget that freedom exists, for she only has to look at the fen.