Answer:
Mrs. Braling is NOT aware that the man she is sitting with in the room is not her husband.
Step-by-step explanation:
In Marionettes, Inc. Mrs. Braling is a controlling wife who never lets her husband do anything he enjoys. She trapped him into marrying her and their marriage is loveless and lacks affection.
When Braling duplicated himself to deceive his wife so that he can go and enjoy himself, Mrs. Braling does not realize it since the duplicate Braling has been acting exactly as the real Braling. She has no idea that she has been sitting with a duplicate of her husband, this can be confirmed when in the end of the story she gets surprised when someone kissed her cheek, saying “Why—you haven’t done that in years,” This shows that even though the duplicate confesses to Braling that he is in love with Mrs. Braling, he has not been acting out of character, so she is completely unaware that the man she has been sitting with is not her husband.