Answer:
They explain that the speaker wishes she could exchange her mother's brooch for her mother's courage.
Step-by-step explanation:
The 2nd and 3rd stanzas are:
The golden brooch my mother wore
She left behind for me to wear;
I have no thing I treasure more:
Yet, it is something I could spare.
Oh, if instead she’d left to me
The thing she took into the grave!—
That courage like a rock, which she
Has no more need of, and I have.