I've revived this old thread to let you know that more information has come to light on WikiTree. All of Marina's children have been traced and some of their descendants have. This is the result of the Living Tradition article that I wrote being posted online.
We started this research 40 years ago the old-fashioned way, by hands-on research. As you might imagine I am quite pleased.

https://www.wikitree.com/wiki/Sartin-374