Molly is the sensitive type. Her feelings are easily hurt, and she gets embarrassed very easily, but she can have the courage to do things right.
When Molly first came to the railway, Emily laughed at her for hauling "empties". Molly's feelings were hurt, so Thomas came up with an idea. He had workmen decorate Molly's trucks with lanterns and cover them with tarpaulins, to make them look special to the other engines. The wind, however, blew off the covers in front of Gordon, Percy and Emily. Molly ran away, embarrassed, until she learned that engines at the depot needed her trucks to carry coal. When Molly arrived at the depot, Edward, Henry and James were grateful to see her; but Gordon was annoyed when he had to wait at a signal for Molly's and Thomas' trains to pass