Though your situation may not be the same, here is a citation that references how to approach the task and has some samples. How to Write a Letter to the Judge for Victims of Rape, Domestic Violence, and Child Abuse
I have been a country prosecutor and, trust me, if your letter was perfect the judge would think your lawyer wrote it and just ignore it. Write from your heart. Say what you feel. Be confident. Do not fix all the errors. Make it look like it came from your kitchen table. And ... don't take offense at this... STOP WORRYING SO MUCH ABOUT WHAT THE LETTER LOOKS LIKE AND WRITE THE DAMN THING. I used to tell DV victims to do this:write an entire page top to bottom and do NOT (1) re-read anything you wrote, or (2) correct or change any spelling or grammer. Now, ready set GO!!!!!
Don't be mad at me, I am trying to get you to focus on what is important.