I need help writing a letter for my friend to a judge.?

I don't know that there is any lace you can go for that, but you don't need a special format. Just write, in your own words about the relationship you have with her, how great she is with your kids and the positive changes you've seen in her life just since you've met her. Talk about how hard you've seen her work to improve herself and what a good, sincere person you believe her to be. You can also try talking to her lawyer, with her permission, and ask for help writing it.