What does Mrs. Hopewell mean by "good country people"?
Much like her daughter, Joy-Hulga, Mrs. Hopewell is somewhat critical of others. She, living her life in the country, only finds herself trusting people much like herself. She surrounds herself with a limited few whom hold the same values that she does.
Mrs. Hopewell only trusts Christian country people. It is this fact which allows Manley Pointer to gain access to her home and to her daughter. It seems that Mrs. Hopewell, while staunch in her stereotypes, limits her own ability to judge others correctly based solely upon their claims of being Christian and "country".
Therefore, Mrs. Hopewell defines "good country people" by comparing them to herself and the values she holds. Good country people are honest and good hearted. They also will accept hospitality of others like themselves. Above all else, they must have strong Christian values.