Just an extra thought on the idea that Madame Schumann was instrumental, in her rôle as teacher, for the promotion of her late husband's music by sending out a number of "torch-bearers" into the world to carry on her work.
Another great teacher, Leschetizky, who numbered amongst his students such luminaries as Schnabel, Paderewski, Brailowsky, Friedmann and Moiseiwitsch, apparently became very tired of students bringing along Schumann's Carnaval to his lessons and recommended that they play the "Carnaval Mignon" by Eduard Schütt (another of his pupils) instead; "That's a real carnival!" he was reputed to have said.
I suppose the moral of the story might be that, for all its charms (slight though they are) Schütt's Carnaval Mignon didn't really catch on with audiences or pianists in the way that the Schumann work did, and if the likes of Moisewitsch and Friedmann ever had it in their repertoires they soon dropped it, whereas the music of Schumann was retained.
Who knows, if Schumann hadn't had a champion in the form of his wife, his music might have drifted into obscurity....at least for a while. But if lesser composers (to my mind) like Alkan and Berwald have been re-discovered and championed in the past 50 years or so, it seemes unlikely that Schumann's works would have lain gathering dust for ever.