Is Laura only a wayward drifter, just as her mother says?

I think there is some truth to this. She spends her time polishing her collection of tiny glass animals, her "glass menagerie." Her presence is almost ghostly, and her inability to connect with others outside of her family makes her dependent on Tom and Amanda. Jim's nickname for her, "Blue Roses," suggests both her odd beauty and her isolation, as blue roses exist nowhere in the real world.