With the West German national team, she won a bronze medal at the 1989 IIHF European Women Championship and participated in the inaugural IIHF Women's World Championship in 1990. Fellner went on to represent Germany at seven World Championships, in 1999, 2000, 2001, 2004, 2005, 2007, and 2009; four European Championships, in 1991, 1993, 1995, and 1996; and in the women's ice hockey tournaments at the 2002 Winter Olympics in Salt Lake City and the 2006 Winter Olympics in Turin.