There are three books in the Prairie Skies Series by Deborah Hopkinson, a series about life in Kansas in the mid 1850s. In the first book, Pioneer Summer, 8-year old Charlie and his family move from Massachusetts to Kansas when his abolitionist parents hear that soon to be made a state Kansas has not been declared a free state or a slave state, but that it's status will be decided by the people who live there. They move to a farm near Lawrence, Kansas, even though Charlie does not want to leave Massachusetts, his grandpa, and his dog.
In the second book, Cabin in the Snow, Charlie must grow up and show that he can help take care of his family, when his father stays behind in Lawrence to help defend the town from pro-slavery brigands. Charlie must get the supplies home to the family and help keep them safe through a blizzard.
The third book is called Our Kansas Home, and the Keller family has survived the winter, but now Charlie's father is in danger for his involvement in the free-state movement and must go into hiding. Once again, Charlie must take care of his family, as well as Lizzie, a runaway slave he finds hiding in the grass.
I plan to use these books whenever we study this period in Kansas history. They show realistic experiences a family might have had during this turbulent time period. The three books are each about 13-14 chapters, about 70-80 pages long. They deal with serious topics, and speak of violence, though there is nothing graphic. They are suspenseful in parts, but not overly so, and they do not advocate violence as a solution. Much of the story focuses on Charlie as he grows and matures, and we see the historic events through his eyes. I would not have a problem with Catherine reading them, as long as we had discussion to go along with them.