Judy Jetson is the Jetson’s boy crazy 15 year old daughter. 15 rather than 16 because 16 was then the known end of all teenage innocence and the show would have had to explore issues unbecoming a cartoon. 15 is the age for a Quinceanerara, a coming-of-age party in Latin culture, clearly women mature faster there, and a Latin Judy would have had to have been 14.
Judy is a loving sister and daughter, but generally gets her own way by manipulating her parents. She stays as far away as possible from chores, “but Mom, you know I hate doing laundry”. Her age (counting again from 1962, not 2062) puts her squarely in the upcoming Me Generation and the signs are already there.