Final answer:
In 'To Kill a Mockingbird', certain characters have known another character for a long time but were unaware of certain aspects of her. This can be attributed to her reserved nature and the failure of others to pay attention. Mrs. Hale's realization about the bird cage is an example of this.
Step-by-step explanation:
In the novel 'To Kill a Mockingbird', there are characters who have known the character referred to as 'her' for a long time but never knew certain things about her. This can be attributed to various factors such as the character's reticence or reserved nature, which may have prevented her from revealing certain aspects of herself. Additionally, the characters may not have paid attention to details about her until a significant event or moment occurred, prompting them to take notice. An example of this can be seen in the passage where Mrs. Hale realizes the significance of the bird cage after the murder of Mr. Wright.