Answer: Anne Frank used to write letter to her friend Kitty.
Step-by-step explanation:
Anne struggles with the isolation in the diary of a young girl. He suffered from being alone and also with the boredom of being secular in the Secret Annexe. She was hiding herself and was in the fear of being caught. She used to write letter to her friend her name was Kitty in order to mention her fear, anxiety and boredom which she was suffering these are indicative of her man vs self conflicts, fight with oneself. She mentioned the letter to her friend Kitty in the daily dairy entries.