glass symbolism

In The Glass Menagerie, Tennessee Williams makes the symbolism between Laura and her glass very clear from the very beginning.  "She is like a piece of her own glass collection, too exquisitely fragile to move from the shelf" (Williams, 1234).  For me, the glass figurines symbolized three things: limits, fragility, and breaking out of one's shell.
In the time of this play, women had two options if they were to survive: get married, or get a job.  A woman could not usually travel and escape her life like Tom wants to.  I think the glass figurines represent, in a way, Laura's limits as a female of that time.  I noticed that whenever it was suggested that Laura either go back to school, get a job, find a husband, etc, she would consider the prospect initially, but then turn to her glass.  It was as if the glass reminded her, WARNED her, that she shouldn't get her hopes up too high.  They urged her to stay where she was, not to try and push the limits on what an acceptable woman could do.
Clearly the glass collection is symbolic of how fragile Laura is, both physically and psychologically.  She shattered inside just as much as her ornaments did when Tom accidentally broke some!  However, I think they also stood for breaking out of one's shell.  When the horn of the unicorn broke off when Laura and Jim were dancing, she was not upset, but instead said it was a good thing.  She stated that, now, that figurine felt no different from the other horses of her collection.  Jim made Laura feel so comfortable, and so confident in herself for the first time, that, for a moment, she felt no different from anyone else.