Dr. John K. Martin and Mrs. Bonnie Martin of Gainesville announce the engagement of their daughter Miss Kendley Gayle Martin to Mr. John Marshall Heffner Jr., son of Mr. John Marshall Heffner Sr. and Mrs. Lisa D. Heffner of Lawrenceville. The bride-elect is the granddaughter of the late Mr. John K. Martin Sr. and Mrs. Frances T. Martin of Atlanta, and the late Mr. Elmer L. Stanley Jr. and Mrs. Jerry B. Stanley of Atlanta. She is a graduate of North Hall High School in Gainesville.