Marina Nikolayevna Prusakova
Nikollayevna..... Means that Marina was born out of wedlock.....Marina's father was named Nikolai and her mother's name was Prusakova..... And Marina's name was Marina Prusakova. Nowhere did she ever use the name Marina Nichilaveva.....
I don't believe that Lee was simply misspelling a word that means that Marina was the illegitimate daughter of Nikolai....I believe that Lee had learned the name of a Russian agent named Nichilaveva.....and was passing that info to the FBI....