The Stone Angel contains rich symbolism, which enable its audience to gain insight about the main character, Hagar Shipley.
The symbol of the bird – at one point Hagar injures a sea gull and it lies on the ground beating its wings helplessly. This is symbolic of Hagar’s own lack of freedom. Her reality is that of old age, which renders her unable to do the things she has always done for herself (a very frustrating experience).
The stone angel itself represents Hagar herself. She is very much like a statue: cold, unfeeling, and hard. When Hagar’s son, John, dies (the child she favours), she metaphorically turns to stone and cannot weep for her loss. The fact that the statue does not have eyes also symbolises Hagar’s lack of insight into herself. She is blind when it comes to others and can only see the world through her own self-centered eyes.
I hope that this helps.