Married Sister's Name First on Envelope?
My fiancee has two married sisters. When addressing the outer envelopes to them and their husbands, is it appropriate to forego the traditional "Mr. and Mrs. John Doe" and put her name first (e.g. Jane and John Doe), or do you still follow tradition in this case and put the husband's name first, even though he is not directly related to the groom? None of the etiquette websites I have checked deal with this specific question. Thank you in advance for your help!