Final answer:
The simile in the provided sentence is "as cranky as a mama bird trying to protect her nest," which compares Jonah's mom's mood to a protective mother bird.
Step-by-step explanation:
The sentence provided from the student's question contains a simile. A simile is a figure of speech that compares two different things using the words "as" or "like". In the sentence "However, there were a few times when I spent the night at his house that she was as cranky as a mama bird trying to protect her nest," the comparison of Jonah's mom's crankiness to a mama bird protecting her nest is a simile. It vividly describes her protective and perhaps irritable behavior by likening it to a common characteristic of mother birds.