We're so happy to welcome you to the family! Respect her boundaries.I wanted to share an open letter to my future daughter in law. Dear Daughterinlaw, Today, you enter our home with new dreams and hope. In you, I see my reflection from a long time ago. A "thank you for joining" membership letter should include a personalized greeting to the new member. Use the member's first name in your salutation. Sharing thoughtful quotes is a great way to show your fabulous daughterinlaw how much you care. Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization. Letter to my new daughter in law.