Dear Saint Nicholas,
My name is Effy and I'm 13 years old.I am writing you because I have some wish.But this is no ordinary desire.I would like to wish to my family and friends were always happy and healthy.This is the most important for me, because for me nothing is more important than my family.I really hope that you read this letter.
Best regards,
Effy.
Тут вы только поменяйте имя на ваше,ну и ваш возраст:)