hillbilly - A person from a rural, mountainous area of the United States, especially the Appalachians. Can be used in an insulting manner.

The hillbilly family made a store in Alabama, and its theme is that the families in rural America may not be sophisticated, but they have a big heart and close family ties.
promiscuous - Lacking discretion or selectivity, especially in choosing relationships or associates; mixing or combining things randomly.

The character in the novel was portrayed as promiscuous, frequently engaging in relationships without commitment or emotional attachment.