Dowager Empress Marie Feodorovna never once received her son Grand Duke Michael's morganatic wife, Madame Brassova and her son, Count George Brassov.
I've often wondered, if the marriage would've lasted had Michael survived the revolution, considering Natasha had already two failed marriages.
Still those morganatic wives were, though not fully accepted in the family, brave enough to try to save their husbands. Olga Paley wanted to save GD Paul, Natasha drove to Moscow to personally speak to Lenin (of course she wasn't let through).
At least Prince Gabriels later wife Antonina Nesterovskaya was successful with the help of Maxim Gorky.
I think Maria Feodorovna could've at least received her. I think that Michael meant a lot to both of them.