In The Glass Menagerie, weakness is linked to fragility, which comes to mean both beauty and breakability. While Laura’s shyness and fragility keep her in her own little world of equally fragile glass animals, they also infuse her with a mysterious individuality, something Jim picks up on with the nickname "Blue Roses" and finds incredibly attractive. Fragility also means dependence, as Laura needs Tom precisely because of her shy and delicate demeanor. We also see the relationship between physical and mental fragility, as it seems that Laura’s shyness arises from a physical defect: her crippled leg.
Despite her attempts at helping, Amanda is the character primarily responsible for Laura's fragility and shyness.
The Glass Menagerie makes it clear that there is no hope for Laura; while Tom escapes, Laura is left stuck in an inescapable rut, a prisoner in her own glass house.