Chapter 12, titled "I Will Not Be A Slave," begins with Lyddie working on the factory floor. She has gotten into a solid rhythm working the machines and feels good about the work. It seems that the overseer has also noticed. When a group of foreign dignitaries visits the mill, they are briefly taken over to Lyddie's station to watch her work. This makes Lyddie very proud yet self-conscious.

Now that Diana has gone, Lyddie has no friends on the factory floor. This lack of distraction allows her to work harder than ever and her pay reflects this. However, she still reads passages from Oliver as she works.

One day a letter arrives from her mother. In it, Lyddie's mother expresses her surprise that her daughter has become a mill worker. She asks that Lyddie send some money to the family, something that she had been meaning to do. She also learns from the letter that little Agnes has died and Rachel is ill. Lyddie is struck that she can barely remember what Agnes looked like and that she finds herself unable to cry. After reading the letter, Lyddie resolves to work even harder so that she can save enough money to reunite her family.

Back in the dormitories, Lyddie and Betsy spend most of their time reading. This annoys Amelia, who urges Lyddie to stop reading and join her on a Sunday afternoon walk. Amelia snags the book from Lyddie and insults it. Lyddie gets angry, and they argue until Betsy interrupts and puts Amelia in her place. They soon get to talking about how they are being overworked. Maybe they should sign the petition demanding shorter workdays. There is a heated debate about notions of justice and fairness in the workplace. Betsy seems eager to sign it even though she risks being dismissed. Lyddie, however, decides not to sign on because she feels she needs the money too much to take the risk.

Chapter 12 is titled "I Will Not Be a Slave." The chapter begins with Lyddie working on the mill floor. Conditions are terrible, but Lyddie is working above and beyond what other girls are doing. She is doing so well that Mr. Marsden shows her and her work to some visiting foreign dignitaries. Mr. Marsden says that she is "one of our best girls." Readers are then told that all of her unceasing, good work is paying off financially too. Lyddie is making almost $2.50 per week above her $1.75 board rate. She is still working her way through Oliver Twist, and she reads each copied page so often that she practically has them memorized. We get a little narration about how Lyddie is starting to be able to analyze the text and do basic character breakdowns.

About a third of the way into the chapter, Lyddie receives a letter from her mother. The letter is full of bad news and is extremely depressing. It asks Lyddie for money, saying that Agnes and many others have died and Rachel is also not doing well. The letter causes Lyddie to decide to work even harder to earn even more money in order to pay back the family debt. The goal is that the family can eventually be reunited. She takes on four looms all by herself, and she is able to keep up with the increased pace when other girls are not. Prudence, one of Lyddie's roommates, goes home for good. It is mainly for health reasons.

Readers are also told in this chapter that roommate tensions are running a bit higher. Betsy is studying like crazy, and Amelia is driving everybody crazy with her continual talk about the Sabbath and "stretching your souls." Tensions are stretched to the breaking point when Amelia claims that novels, including Oliver Twist, are the "devil's instrument." The conversation eventually moves to working conditions, and Betsy claims that they are all working "like black slaves." Betsy also expresses a possible desire to sign the petition. Lyddie is appalled at the very thought. Girls that sign the petition are blacklisted, and they no longer can earn any money. Lyddie is adamant that she keeps the job and the pace, and she defends the idea that she is not a slave. The argument ends when the curfew bell rings, and the chapter ends at that point too.

In chapter twelve, the book describes how Lyddie is now tending the same number of looms, yet they run much faster, increasing the workload significantly.  She doesn't mind, though, since she is paid well, at least in her opinion.  She reads Oliver Twist when she has time, to improve her reading skills.

She receives a letter from her mother saying that her little sister Agnes has died and asking her to send money to help support the other two children.  She struggles a bit with hearing that Agnes died, and resolves to work harder so she can pay off the family's debts.

She also gets into an argument with her roommates.  Amelia feels that they should all be more religious and criticizes Lyddie for reading Oliver Twist on the Sabbath.  Betsy feels that the girls are being treated like slaves at the factory and is determined to stage a walk-out and then leave to go West.  She also toys with the idea of signing the petition that has been circulating.  Lyddie, of course, feels desperately that either of these is the wrong course of action because it would leave them without a job.  They argue for some time about it without coming to any conclusion.  The chapter ends as the curfew bell clangs and they settle in to sleep for the night.

I can give you a brief overview of the chapter, but I suggest you go to enotes and read over the events again so you better understand.

Lyddie gets a letter from her mother telling her that her little sister, Agnes, is dead. This makes Lyddie work even harder, and she doesn't even complain when the machines are made to go faster in order to increase productivity.  Prudence quits her job at the factory, nursing a cough that doesn't go away. Conflict among the girls is caused by the petition that is being circulated to improve working conditions at the factory. Betsy wants to sign it, feeling they're treated no better than slaves, but Lyddie wants to keep things the way they are so she can make as much money as she can for her family.