We're so happy to welcome you to the family! You will always be the most important girl in Tyler's life which makes you very important to me.The day he proposed to you, you became family! Dear Daughterinlaw,. Today, you enter our home with new dreams and hope. 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. Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization. An open letter to my future daughter in law. I knew when God gave me that precious little boy, the day would come when I would have to let him go.