In 1999, Miller resumed her on-camera acting career with recurring roles on the Nickelodeon series The Amanda Show and All That and on General Hospital. She also began working in animated series, lending her voice to various characters, including Kari in Digimon (both the series and the feature film), Koko in Zatch Bell!, Alejo in Astro Boy, and Scheris Adjani in s-CRY-ed. Miller also provided the singing voice of Dorothy Gale in the National Public Radio adaptation of L. Frank Baum's The Wonderful Wizard of Oz, and the voices of the title characters on Cartoon Network's The Life and Times of Juniper Lee, Disney Junior's Henry Hugglemonster, and the PBS Kids Clifford's Puppy Days (prequel to Clifford the Big Red Dog).