The opening description of "Miss Brooke" (a.k.a. Dorothea) harps on how she's so beautiful that she doesn't need to wear fancy clothes.
In fact, she wears very plain clothes, despite her good birth – her family is solidly part of the lower upper class. Women of the middle class, the narrator tells us, try to show off by wearing fancy, expensive clothing, but Dorothea Brooke and her sister Celia don't need to show off.
But Dorothea doesn't choose plain clothes for social reasons, or even to save money for more important things: she wears plain dress because of her religious beliefs.
Dorothea is so hung up on her spiritual life and its "eternal consequences" that she thinks it's crazy to spend any time worrying about clothes.
Celia is easy-going enough to go along with her sister's ideas about wearing simple clothes, but her common sense tells her that such ideas can be taken to the extreme.
Dorothea and Celia have only been living with their uncle at Tipton Grange for about a year.
Before that, they lived in Switzerland, where they'd been educated.
Dorothea, the older of the two, isn't quite twenty yet – the girls had been orphaned when they were twelve, and their uncle Brooke, who isn't married, decided to send them away to school rather than attempt to raise two girls on his own.
Dorothea says she doesn't want to marry – she has too many ideas about how to help her uncle manage his estate and improve the lives of the poor people in the neighborhood.
Her wealth and beauty, though, would make her an attractive wife for anyone – if it weren't for her extreme ideas about religion and reform.
In fact, a neighbor of theirs, a young man named Sir James Chettam, has been visiting them so often that Dorothea assumes that he must be in love with Celia. Of course, he's actually in love with Dorothea, but she's too busy thinking about how to help poor people that she hasn't realized it.
Celia and Dorothea are alone one afternoon.
Celia asks Dorothea if they can go through their mother's old jewelry box together – now that they're old enough to wear grown-up jewels, their uncle has given them their mother's to split up as they see fit.
Of course, Dorothea isn't interested in jewelry. Too superficial!
Celia, though, thinks the jewels are pretty, and sees no reason in the world why they shouldn't wear them – if only to honor their mother's memory.
Dorothea acts like she's above such things, which hurts Celia's feelings.
Then an emerald ring and bracelet catch Dorothea's eye – the brilliant green is so gorgeous that she agrees to take those things, and let Celia have the rest.
Celia agrees, but is still annoyed that her sister should be so eccentric when plenty of women – even good, devout Christian women – wear jewelry.