Astar's first television role was that of the young "K.C." Koloski on the drama series China Beach in 1991. Star Trek: Voyager veterans Robert Picardo, Jeff Kober, and Concetta Tomei were regulars on this series at the time. Astar made her film debut that same year, playing Elizabeth in the comedy Ernest Scared Stupid. She again worked with Robert Picardo in the 1992 film Samantha, in which Astar played the title character as a child while Picardo played her biological father.