Your post seems to resemble an assignment one would receive when reading "The Crucible". This being said, I want to help you help yourself. So, I will provide the information which you will need to complete the assignment in your own words.
Abigail Williams is removed from service at the Proctor's house given that Elizabeth Proctor has become aware that her husband, John, and Abigail have had an affair.
Not only is the affair inappropriate given that John is married to Elizabeth, the high moral code that the Puritans held would look down upon the relationship as well.
That being said, the diary entry would need to include information as to how Elizabeth gained the knowledge of the affair. This is not directly stated in the text. You will need to create the circumstances by which Elizabeth found out about the affair.
You will also need to describe Elizabeth's feelings about Abigail and about her husband. She knows that she must let Abigail go, she cannot risk the affair's continuance. Also, how does Elizabeth feel about her husband? Is she going to forgive him? How will she insure that their marriage will survive? What does she see in the future? What are the possible revenge tactics which she fears from Abigail?
If you answer all of these questions you will be able to create a diary entry as assigned.