If everyone is being addressed with a title (ms/mr/professor/whatever) then those who have earned a dr title should be addressed as such (be it medical or academic). But if the general protocol is first names, then hell no. I imagine she's talking about professional social gatherings -she probably doesn't do any other type.
Child's piano concert? Well if you're schmoozing, then yes, but if you're just being friends, then no.
But you should never address a Dr as a Mr or Mrs if titles are the theme of the day -especially not the Mrs thing. Mrs means belonging to Mr. Most women who have worked hard to earned the title Dr. will have an objection to that -especially if they didn't change their last name.
Of course, I could be unrepresentative of the sample, but I get major pissed if you address me formally and know I have a doctorate and still call me Mrs. I can forgive you if you don't know -as many don't because I don't work- and I won't even correct you (unless you really piss me off), but if you know, I take it as an insult and I will never tend to you if you have a heart attack in public and I'm the only Dr in the house
