Symbolism, Imagery, Allegory
One of the worst things about dying has got to be having your family go through all your stuff. Gemma didn't keep a diary or anything like that, but she did have a wooden box—with a rose carving on top, of course—where she stored some personal effects, including a lock of hair, her immigration forms, and some photographs.
Looking through this box of secrets after Gemma's death, the Berlin family finds evidence of a life they never knew she had. Becca is fascinated by Gemma's mementos, which she refers to as "signposts."
"Why had Gemma kept them secret?" she wondered. "And what had any of them to do with the story of Briar Rose?" (6.25) Combing over these materials carefully, Becca is able to find enough clues to set her on the right track. Signposts, indeed.