Final answer:
The object that is personified in the sentence is the fog, as it is described with the human-like action of being able to 'crawl' away from the shore.
Step-by-step explanation:
In the sentence "Our family woke early the first day at the beach house and watched the fog crawl quietly away from the shore," the object that is personified is the fog. Personification is a figure of speech where human qualities are given to animals, objects, or ideas. In this case, the fog is described as being able to 'crawl,' which is a human or animal action, suggesting that the fog is moving slowly and deliberately away from the shore, much like a creature might.