The courteous thing to do is to

invite the provider to dinner at your house to meet your wife (and kids if they're home from college), and get a bit of feeling straight from the "horse's mouth" as to what you like, dislike, and don't get enough of at home.  Also, providers love to hear all about your marriage woes, if any.  Seriously, though, there have been at least some posts from providers on this topic basically saying they don't feel it's any of their business.  There was also a recent thread about "should I remove my ring" and if I recall correctly the response was "most guys don't and why should they?".  I'm not a provider, so now I'll shut up so we can see what they say in response to your question.....

The envelope is her only concern

Although I guess the ring says it all... In a way, it is good to know the marital status, I would be scared of a crazy wife sending me texts from his phone..At least single guys do not have that complication sometimes...

and unlikely to become stalkers.  Gents who remove rings still have marks & tan lines...  if they wear a ring...  and risk misplacing it.  I have seem married providers who wore their rings through out.  Some chose not to.  There's no need to discuss it but in most cases it will come out eventually.

No need to bring it up.  Honestly they don't care either way, as they just assume that most of their clients are married anyway.  

If you were a plumber, or an auto mechanic, or a doctor, or a banker, and your client randomly told you that they were married, you probably wouldn't care either.  What you would probably care more about is if they paid their bill and then left.  

By the way, if you wear a wedding ring, there is no need to take it off when you see a provider.  That won't make any difference with anything.

Some providers don't want to hear sob stories about your wife but IMO a true GFE listens to it and hopefully is comforting.