Theory:

This story is an extract from the Novel "The Adventure of Tom Sawyer". Tom Sayer stayed with his aunt he never liked to go to school unless one day a girl name Becky started to come to school. Becky stopped coming to school due to some reason, and Tom again went back to his tantrum for not going to school. His aunt loved him very much and tried her best to coax him to be happy and go to school.
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Tom giving pain killer to Peter

Aunt Polly came to know about new types of medications and tries it on Tom Sawyer as she could not see him dull. Initially, she started some water treatment like sitz baths, shower baths, hot baths, etc., but to no avail. Then she started giving him some painkillers. Tom played a prank on his aunt and gave the painkillers to her cat "Peter". Peter reacted mysteriously, and aunt saw them all. When confronted Tom, said that he was trying to be the cat's aunt. Aunt Polly felt bad for him and stopped him from taking medicines further.