She believes she's entitled to use resources like the US consulate for personal purposes. She also pulled that stunt because she was caught out in several lies about having contacted her father, so in her mind having fuss and bother about handing over a letter wipes the slate clean. This thing can also be used when she chooses to contest her father's will or announce she's going to his funeral because that letter proves her love for her father. We all know that's hogwash, but that's what she'll do.