Plays the younger sister on the hit show "8 Simple Rules... for Dating My Teenage Daughter" (2002), but she is 6 years older than Kaley Cuoco, who plays the oldest daughter. Amy Davidson Detailed Biography Amy Davidson (born September 15, 1979 in Phoenix, Arizona) is an American actress, best known for her role as Kerry Hennessy in 8 Simple Rules. Although her character on 8 Simple Rules is younger than her on screen sister (played by Kaley Cuoco), Davidson is in reality, six years older than Cuoco. A native of Phoenix, Arizona, Amy began doing commercial work and her acting coach Gene Fowler encouraged her to move to Los Angeles, California at a young age. Upon arriving in Los Angeles, Amy was cast in the Mary-Kate and Ashley Olsen series, So Little Time. She has also guest-starred on the drama series Judging Amy, and appeared in the movie The Truth About Jane. Most recently, Amy wrapped production on the Hallmark Channel original movie Annie's Point, opposite Betty White and Richard Thomas.