There is not enough information available to determine precisely what role Julie Hagerty played in 'Christmas Story'. However, considering her acting abilities, she could have been cast as a character who added a touch of warmth or humor to the story. She might have been a character who had a special connection to the main characters, like an old family friend who shows up during Christmas and has an impact on the family's celebration.
Since we don't have a lot of information about Julie Hagerty's part in 'Christmas Story', it's possible she played a supporting character. Maybe she was part of the background characters that helped to set the scene of the Christmas - time community. For example, she could have been in a scene at a local Christmas party or a church event within the story, adding to the overall Christmas feel.