In discussion with Schulbildung in Familieninitiative e.V. it was suggested that enclosing a brochure that is readily downloadable and already written in German with your letters, from their website, could be a valuable idea.
Have a look at "Homeschooling" or "Freiheit für Bildung" (Freedom to Educate).
This will add only a few cents more to your material costs, but bridges the language barrier where the recipients english is not as fluent as their mother tongue.
Sitting down last night drafting the letter I am to send to the "5 Women in Power" seemed like an insurmountable task - to keep it short and sweet that is. I think I will add an appendix to the end instead of quoting everything in the body of the text. There is so much I want to tell them! LOL. I have given myself a 2 page maximum!
How are your letters going?