As far as I’m concerned, it is, and should be, a nonissue. She doesn’t have a formal role; it’s a traditional one.
(I will muse here that it’s usually the conservatives who are accused of looking backwards to tradition and being resistant to change. In this case, it’s the “liberal” critics of Trump who are the ones looking backwards. Interesting role switch, that.)
So, for all I care, she can say she’s staying in NY because she doesn’t like the drapes in the White House, and that’s good enough for me.