What everyone else said! It's so important for us to share cultural differences with others and in so doing, find common ground to celebrate.
I don't have any advice on how to conduct your "class" except to keep your designs and stitching on the simple side to begin, and perhaps you could explain to the english-speaking ladies that you are unfamiliar with their customs and perhaps they could advise you and give you some information so you don't unintentionally offend anyone. I'm sure they will be very understanding and most cooperative. I think your project will be really successful - after all, women are women everywhere with many of the same goals and interests. You'll probably learn a lot from them, too.
Good luck, have fun and please let us know how it's going!
Also, should you need fabric or any supplies, please let us on the Board know. We'll be glad to help.