Judy

In the first letter , Judy tells Daddy about her first days in college . She shares her anxieties and worries . She tells about her failures and mistakes that she makes from the first day of study . Having read the letter , we can imagine an unsure , slightly educated girl who is just beginning to learn the world . 
In the second letter , she tells about her study in the second year of college , about the new subjects she is studying in college . Here I can imagine an adult , self-confident, educated girl who has her specific goals and seeks to realize them .
I think her last words mean that she is going to study all her life.