Aunt Effie Harper is Thelma Harper's sister-in-law. Originally, she was named "Effie Crowley" and she was referred to as "Cousin Effie". Effie is generally considered to be crazy, and she provides a good laugh with her antics and ever-present rum balls. It is never mentioned how old she is but Vint once remarked. “Why Aunt Effie, she’s three days older than God!”
She was portrayed by Dorothy Van.