After all, Julia said, everyone who auditions gets a part, and the girls had been practicing many of the steps they would be asked to do in their dance classes.
"We've watched it so many times, we can do it all," said Ellen, who will be dancing in the production for the fourth time this year and remembers watching her cousin in it before that.
The girls, dressed in black leotards and tights, and wearing matching pink and purple nets over their buns, received hugs and wishes of good luck from their mothers before rushing down the stairs to join the dozens of other 8- to 11-year-olds in their audition group.
Inside the audition room, former company ballet mistress Jennifer Green-Flint guided the group through a series of moves that included as much vigorous soldier marching and sneaky mouse creeping as graceful skipping and bourreing across the room with "pretty arms."
Julia was called forward, along with some of the other smaller girls in the group, to show off her cartwheel, while Ellen was asked to try a scene in which Fritz grows angry at his sister Clara and another in which Clara watches the Christmas tree grow magically in front of her.
The judges were watching not just for dance skills, but maturity and the ability to convey emotions through gestures and facial expressions, said Julie Schimmel, who sits on the ballet company's board of directors.
Getting the facial expressions right was the hardest part, Ellen said later.
"You had to make special effects and such," she said.
Julia agreed. Seeing the other dancers making funny faces makes it hard to keep a straight face, she said.
The girls won't find out how they are cast for several days, but as they left Sunday, Ellen had a good feeling about getting cast as a party girl, while Julia thought she might have a chance as a soldier.
And all the girls were left with the encouragement of company president Mike Heyser, who told them three of the audition judges started out playing mice.
"Everything's really, really, really important," Heyser told the dancers. "You've just got to be as good as you can be no matter what part you get."
This year's production will be Dec. 8 at 7:30 p.m. and Dec. 9 at 3 p.m. at The Maryland Theatre.