Kit grows up significantly throughout the book, learning to survive in a different culture.
Kit Tyler goes from being a sheltered rich girl to a generally successful Puritan over the course of the book. The culture she grew up in is completely different from the one she finds herself in when she is in Wethersfield. She grew up in warm Barbados with slaves to do her work, reading Shakespeare and generally living a life of luxury. Wethersfield is cold and harsh, with hard work and strict rules.
One of the first mistakes Kit makes is to jump into the water to try to retrieve Prudence’s doll. This is a huge mistake because no one in Wethersfield swims. The Puritans believe that if a woman is in the water and doesn’t sink, she must be a witch. Kit has no idea about these beliefs. She just wants to help the little girl.
On the ship on the way to Wethersfield, Kit meets Nat Eaton. At first, their relationship is more like a couple of bickering teenagers. They get under each other’s skin. However, Nat is actually one of the few people to understand Kit. He develops an interest in her, and she realizes it much later on. This realization is evidence that Kit is changing, and growing up.
When Kit first arrives in Wethersfield, she has trunks of useful beautiful dresses and no practical skills. Since she wants to be of use to her aunt and uncle, Kit tries to learn how to do household chores. She is used to having slaves to do them. She has never really had to do hard labor. Kit never really comes to enjoy work, but she does get better at it.
Another of the ways Kit is different from the typical Wethersfield resident is that she befriends Hannah Tupper, an old woman everyone thinks is a witch. Nat also cares about Hannah, and comes to help her out whenever his ship brings him in town. This is how Nat and Kit get to know each other better.
Kit seems to understand that she will eventually have to get married. She catches the eye of a very eligible bachelor named William Ashby, who happens to be rich.
If she should many William Ashby, would he expect her to weed his vegetables for him? Her hands stopped moving at all while she considered this. No, she was quite certain he never would. Did it seem likely that his mother, who sat so elegantly in meeting, had ever touched a chokeweed? (Ch. 8)
Although Kit could live a comparatively luxurious life with William, she realizes she is not in love with him. For a while she tries to get to know him, but there is just no attraction between them. When Nat illuminates the house Ashby is building for Kit with jack-o-lanterns, Kit realizes he is jealous. She also comes to the understanding that Nat is in love with her, and she loves him too.
Nat compares Kit to a tropical bird.
Kit giggled. "Are you saying I’ve turned into a crow?"
"Not exactly." His eyes were intensely blue with merriment. "I can still see the green feathers if I look hard enough. But they've done their best to make you into a sparrow, haven't they?" (Ch. 12)
He believes that she will never fit in there, no matter how hard she tries. She realizes that he right. She is much happier traveling the seas with him than trying to keep house in the frigid winters of Connecticut. Part of growing up is coming to understand who you are, and what you really want. Kit does this, eventually.