Sweet and Sour Lily by Sally Warner
    Lily, her mother, and older brother, Casey, have just moved to a cramped apartment because Mom has to work now that Dad's in jail. Starting in a new school, in a new city, is difficult for Lily. She decides she'll improve herself. At her last school, she was 'sour' and disruptive, so she  starts out trying to be 'sweet' all the time. When she gets in trouble with her teacher, Casey explains to her that she doesn't have to be all sweet or all sour, she should just be herself.
 

A Visit to the Big House by Oliver Butterworth.  Mother, Rose, and Willy go to prison to visit Daddy for the first time.

"Amber Was Brave, Essie Was Smart" by Vera B. Williams is a book of poems about how two girls deal with a working mother and a father in jail.  heir father is in jail, and this story deals with their emotions while he is gone. (He does come home at the end of the story).  Beautifully written book using poetry, and the voices of both girls and how they are feeling.

"Visiting Day" by Jacquelin Woodson.  It tells about a girl and her grandmother who are going to visit dad  in jail.

"Our Gracie Aunt"  by Jacquelin Woodson. It tells the story of 2 children whose mother is going  away and this time she won't be back. A
social worker takes them to meet and live with their Aunt Gracie, who they don't know. The children deal with worries about their mother and learning to build a new family with their aunt.