Everything you need to write a declaration letter to the judge in your custody case: an example, a downloadable template, an outline and tips. Affidavit of Child in Support of Motion for an Order for Sibling Placement or Contact.These forms and instructions are available in the General Clerk's Office, Room 108, in the Nassau County. Give it to your attorney to get it into the record properly. What parents and witnesses need to know about character reference letters to the court for child custody. Includes a downloadable sample and template. This article provides a comprehensive guide to writing a declaration letter for child custody cases, including a sample letter. To write a parent custody letter, you should follow a formal structure and clearly express your intentions. Here's a general outline to help you get started. If there is a Children's Lawyer or Child Advocates office, ask them to investigate.