In addition to appearing in the 1994 premiere of popular NBC medical series "ER" in 1994, Appleby could be seen portraying a young woman caught up in a street gang on a 1997 episode of "7th Heaven". During the 1998-99 season, Appleby had an amusing recurring role on "Xena: Warrior Princess" playing Tara, an aspiring young warrior who seeks to take Gabrielle's place as Xena's sidekick. After supporting roles in the 1999 features "The Other Sister" and the time-travel thriller "The Thirteenth Floor", she landed a starring role in the cult hit "Roswell" (The WB, 1999-2001; UPN, 2001- ), playing Liz Parker, a high school student and part-time waitress in the New Mexico town known as the site of an alleged 1947 UFO crash. Trouble comes to the restaurant where Liz works (owned by her father), and she is shot but miraculously healed by mysterious classmate Max (Jason Behr), an alien who has taken human form. Liz must then keep his secret, helping him and his alien compatriots Isabel (Katherine Heigl) and Michael (Brendan Fehr) dodge suspecting authorities. Part sci-fi adventure and part teen drama, the series proved an enjoyable hybrid, with Appleby's portrayal of the confused and sympathetic young woman serving as a particular highlight.