Why is Judith mean to Kit in chapter 4 of The Witch of Blackbird Pond?

Judith resents the fact that Kit has fancy dresses.

The relationship between Judith and Kit is a complex one.  Early on, Judith is fascinated with Kit.  Remember, Kit does not understand the ways of the American colonists.  She comes from a very different place.  These colonists value simplicity and hard work.  Kit shows up with trunks of fancy dresses. 

At first, Judith is thrilled.  She just likes looking at all of Kit’s clothes.  Then Kit offers to give her some.  Judith admires the colorful dresses, and fantasizes about wearing them.  Kit offers her a dress.

Judith was back at the mirror. "Just wait till I walk into Meeting in this on Sunday morning," she squealed. "A few people I know won't hear a word of the sermon!" (Ch. 4)

She also imagines what William, the man she is courting, will say when he sees her in her fancy new dress.  She knows that the dress will attract his attention.  When her father walks in, he tells the girls that they have to give all of the clothes back, and she is disappointed.

Since these fancy clothes are literally all Kit brought with her, because she never really worked in Barbados, she doesn’t have anything to work in yet.  It reminds the girls, especially Judith, of the difference between her lifestyle and theirs.  It creates an instant division between them.  It is as though she is putting on airs and considers herself better than them, even though that is not her intention.

The work that Judith assigns Kit is really just a way of putting her in her place.  Kit also has never done any of the work before, so she is not good at it.

They were such awkward things. The wool fluffed and stuck to her fingers and snarled in clumps. She suspected that Judith had chosen this task on purpose. (Ch. 4)

 Kit begins to think that Judith is just out to get her, but in fact, the work is real.  When she does not take it seriously, she messes it up and they all pay the consequences when, for instance, the family’s cornmeal is inedible.  No one says anything though.

Judith’s frustration with Kit’s inability to work leads to her complaining about Kit sharing her bed.  However, it makes sense.  It is all a big adjustment for Judith.  She suddenly has another instant sister, and has to give up space and teach her how to do things.  Judith’s lack of patience with Kit, and her unfriendliness, makes Kit very upset.

We have to remember that Kit showed up suddenly unannounced.  She did not write to tell them she was coming.  Her presence is just as much a surprise to Judith as anyone else.  Yes, Judith’s behavior is harsh and somewhat rude in the beginning.  However, she has a lot more work now that she has to teach Kit how to do things, and she must realize that one more girl is competition for the eligible men in the community.  Kit is one more girl with a trunk full of beautiful dresses.  Judith not only has to share her bed, she has to share the marriage pool.

What were Judith's thoughts about Kit in The Witch of Blackbird Pond? How did Matthew Wood react when Kit gifted his daughters clothing?

Judith, who tends toward vanity, looks at Kit with envy, perceiving her as someone who has all the things she herself wishes she could have.  Kit arrives at the Wood home dressed in comparative finery. Although the dress she is wearing is plain to her, to Judith, who, like the other women in the family must dress in garments made of "some nondescript sort of coarse gray stuff", it is magnificent, and the thought that Kit has seven trunks full of similar items is beyond belief.  When Judith discovers Kit's generosity, she falls upon the nice things she is offered with undisguised greed.  Judith longs for the pretty things Kit has, but is denied them by her Puritanical father.

When Matthew Wood learns that Kit has generously given his daughters items from her wardrobe, he reacts angrily.  He orders them to give everything back, shouting, "No one in my family has any use for such frippery".  In addition to his disapproval of what he considers to be "unseemly apparel", Matthew Wood reacts with a sense of injured pride, declaring "Nor are we beholden on anyone's charity for our clothing".  Already put out by the fact that Kit has come to live with them unannounced, Matthew Wood is furious that she would "turn the heads of (his) daughters with (her) vanity".  Although he turns a deaf ear to Judith's entreaties to be allowed to keep the gifts, he does relent in the case of Mercy, agreeing to let her keep a simple shawl Kit has given her because it will serve to keep her warm as she sits by the chimney (Chapters 3 and 4).