If you know that they’re not offended by Mr. and Mrs. John Smith, it’s okay to go with that, but as a rule I use John and Jane Smith, or *John Smith and Jane Doe * if she’s kept her name.
Thirding delphica’s response. Nice and neat, and correct to boot.
<rant>
And for God’s sake, don’t try to force a two-surname couple into Mr./Mrs. format. We get mail like this all the time, with abominations similar to this:
John and Jane Smith/Doe
Mr. and Mrs. John Smith/Doe
We each have a name. They are John Smith and Jane Doe. Please don’t conflate them. And if I’m not using his name, I’m not Mrs. Anybody. (I’ll SOMETIMES tolerate “Mr. and Mrs. John Smith,” if I’m in a really who-cares mood that day, but “Mrs. Jane Doe” (Jane Doe being the name I was born with) is just horridly wrong.) The solution is oh-so-simple:
Certainly the advice given so far is valid for the circumstances. Let me point out that in instances where children (in later childhood or adolescence) old enough to understand death and grieve are involved, it is absolutely incumbent to include them in the sympathy note to someone known socially who has suffered a death in the family. This is something commonly skipped, and the inference is that their grief is somehow not valid or important because they’re too young. Certainly a card to a business acquaintance would not call for this, but if you’ve met the family, you should include them.
Not at all traditional but very effective in instances of non-traditional families and households is to address the card to “The Family of Winston Newlydead” – thus including Winston’s daughter, her live-in fiancé, the young woman who officially boards with them and everyone suspects is lover to one or both, or perhaps to Winston before he took sick, the fiancé’s mother and her adolescent son who also live in the same household… It’s not your business what their relationship was to each other or to Winston, or how much each is grieving over Winston’s death. Using that modern style allows them to decide who in the household constitutes Winston’s “family” – as it should be.