Why does Uncle Judah bring Rachel to Lyddie?

Uncle Judah is Lyddie's mother's sister's husband. In chapter 1, Lyddie's mother decides to go live with her sister, and she takes Lyddie's two younger sisters to live with her at Uncle Judah's. When Uncle Judah appears at the boarding house with Rachel, he explains that he has put Lyddie's mother into an asylum for the mentally ill. After Lyddie's father had left the family, her mother "had gone somewhat queer in the head." Uncle Judah and Aunt Clarissa finally find that they can no longer handle taking care of Lyddie's mother, so they have her committed to the asylum at Brattleboro. They no longer want to care for Rachel, the only surviving little sister, and so they bring her to Lyddie. Judah also lets Lyddie know that they are selling the farm to pay for her mother's care at Brattleboro. Having Rachel with her presents a problem for Lyddie because only factory workers can stay at the boarding house. Although having to care for Rachel is a new challenge, Lyddie rises to meet it, and soon is very happy to have Rachel with her.