@Dross3667, I’m on board with the others. The authorities may speculate about Sofia’s parentage, but we (the readers) know the relationships in the Count’s inner circle better than they do. I don’t think Towles is trying to fool his readers. For what it’s worth, this is a trivia question on Goodreads and 83.1% of readers agree that Nina is the mom! https://www.goodreads.com/trivia/show/299554-in-a-gentleman-in-moscow-who-is-sofia