Overhearing parts of Marlon's conversation with Magnezone, it made Marilyn very silent. How difficult it must be to say goodbye to your very first pokemon after all of those years. She couldn't imagine Glaceon not being by her side anymore. 

While thinking of something supportive to say, she suddenly noticed Sonia in the background. "There she is!" At the exact moment Marilyn said this, Sonia noticed them. Marilyn didn't particulary liked her so she let the boys do the talking.