Throughout the winter months, Vermeer continues work on his new painting, a portrait of the baker's daughter gazing out the window. Griet has begun to work as his assistant in the studio. This role begins in January when Griet, sent to the apothecary by Catharina to buy some medicine for the children, is also asked by Vermeer to purchase some painting supplies. After that, he sends her on other errands, and sometimes also asks her to stand in the pose of the portrait's subject so that he can make adjustments to the painting. Griet is careful to try to conceal this arrangement, but the first time she comes back from buying painting supplies, Cornelia sees her and questions her. Griet admits that she was buying supplies for Vermeer but will not confirm whether he asked her to do so. Cornelia responds by breaking Griet's treasured tile a few days later, upsetting her deeply.
As Griet helps in the studio, she is able to observe Vermeer's process. He also explains principles relating to color and design to her, altering the way she observes the world around her. When Vermeer asks her to grind the colors he uses for painting, Griet is forced to tell him that she cannot take on the extra work and still keep on top of her other household tasks. She wonders if this will prompt him to tell Catharina that she is helping him so that her workload will be lessened, but it does not. Instead, a short time later, it comes to light that Tanneke is unhappy having to share her room with the nurse who is caring for Franciscus. Vermeer suggests that if Griet begins sleeping in the attic, then Tanneke can have her room in the cellar. Catharina is initially suspicious of this suggestion: the only access to the attic is through the studio. Vermeer explains that, with the new arrangement, when the studio is locked overnight Griet will be securely kept inside, and also means that she can start cleaning the studio immediately in the morning. Catharina is reassured and agrees.
Even with the new arrangement, which allows Griet extra time to work in the studio, she has to make excuses, claiming to need to go to her room when she actually goes to the studio to complete tasks for Veermeer. Maria Thins is suspicious from the beginning, and after a short time she surprises Griet in her room when she is grinding pigment. She notes that Vermeer has been painting more rapidly since Griet has been assisting him, and agrees to keep the secret.
However, only a short time later Cornelia tricks Griet and smears some of the pigment used for making paint onto Griet's apron. By the time Griet notices, Tanneke has also seen it and become suspicious. She is going to show the apron to Catharina, but Griet intimidates her and tells her that she should take any questions to Maria. Griet manages to achieve silence, but she permanently damages her relationship with Tanneke in the process.
By April, Pieter is becoming more assertive in his attention to Griet. He tells her the story of how Catharina has a mad brother who attacked her in the streets one day when she was pregnant. Tanneke rescued Catharina. Pieter also shows up at the church that Griet and her family attend, and she reluctantly introduces him to her parents. He persists in coming to church with the family and her mother eventually invites him to the house for dinner. Griet's mother is encouraging of the relationship, since she knows Pieter will be able to give her daughter a stable life. As Griet feels increasingly pulled towards him, she begins to allow Pieter to kiss and fondle her.
In this section, Griet finds herself with a new role in the household, and an intensified relationship with Vermeer. When she begins assisting him with the necessary tasks related to painting, she is able to expand her knowledge and gain firsthand experience with his artistic process. This knowledge changes the way Griet sees the world: it becomes a much more complex place with more possibilities than she could have imagined in her sheltered and limited life.
At the same time as Vermeer's entrusting of Griet with tasks reveals that he respects and trusts her, and is able to see the potential in her that many other people would be blind to, it also reveals his selfishness. It does not occur to Vermeer that it is difficult for Griet to balance this additional work with the household tasks she is already obligated to perform. Because of Vermeer's position as a relatively well-off man, he does not have to concern himself with the realities of domestic labor, and remains ignorant of how much work is involved in ensuring that the household runs smoothly. He is also either naïve or willfully ignorant about the risks entailed for Griet in performing this work for him. A maid who seems to be keeping a secret or spending an unusual amount of time with her master will be readily assumed to be having an affair with him, and her reputation and livelihood can easily be lost. Although Vermeer does care for Griet and wants her to have new opportunities and challenges, he prioritizes her potential utility to him over what is best for her.
One example of how Griet's role in the household becomes a dangerous one occurs in the discussion about the possibility of her sleeping in the attic. Although it is not explicitly stated, it can be inferred that Catharina's initial resistance to this plan stems from her suspicions about Vermeer's intentions: she fears that he may be arranging a way to more easily have access to Griet's bedchamber at night. She is clearly aware on some level that Griet poses a potential threat, and she is therefore relieved and pleased when she discovers this arrangement will allow her to keep Griet under lock and key. The locking of the door, which Griet dislikes, symbolizes the desire of her employers to control her and monitor her behavior. Throughout the novel, Griet struggles to find a way to maintain her autonomy even while working as a servant, but these efforts are often difficult.
In addition to tensions with Catharina, Griet also faces a more dangerous adversary in the household: Cornelia. It is never clear why Cornelia takes such an intense disliking to Griet. There is the implication that she is simply a spiteful child who likes to inflict pain wherever she can. She is also intelligent and observant, not unlike Griet herself, and registers the power that Griet has in the household. It is not a coincidence that the more Cornelia can sense Griet achieving a kind of power, the more she tries to assert her own dominance and remind Griet that she is still a servant at the mercy of her employers.