Final answer:
The tone of the excerpt from 'Traveling' by Grace Paley is somber, as indicated by language expressing dread, uncertainty, and a heavy burden.
Step-by-step explanation:
The overall tone of paragraphs 12 and 13 from 'Traveling' by Grace Paley can be described as somber. This feeling is created by the language used by the characters and the reactions to their environment. The phrase 'Oh no' suggests a sense of dread or resignation, while 'Oh, I just don’t know' conveys a feeling of uncertainty and despair. Additionally, the burden of the sleeping child being described as 'mercilessly' hanging from the mother's neck also contributes to this somber atmosphere, hinting at the heavy weight of her struggle.