Did Anastasia live and have a son?
Anna Anderson, the best=known and -probably most feasible
Anastasia claimaint was married, but never had any children. she
had a history of mental illness ( small wonder!) and may have been
deliberately sterilized while she resided in Berlin- the
biographers are silent about this but maybe - this would
effectively forestall any Romanov succession- without harming She
of All The Russias personally!