answer:It is never specified, but her accent and the non-English words that she inserts into her sentences sometimes are both Russian. Her brother is also named “Mishka,” which is a common Russian diminutive name (though oddly enough, “Linka” is primarily a Hungarian name). On balance, then, the evidence tends to suggest that Linka is Russian—and that was probably the impression viewers were expected to get from how she was portrayed. Then again, Gi turned out to be Malaysian despite how many people assumed she was Chinese. So Linka could conceivably be from Ukraine or Belarus (due to the reasonably similar accents and the increased likelihood of Russian being a resident’s primary language). Only Wheeler and Ma-Ti are explicitly identified by national origin in the show, but it is Wheeler and Linka whose characterizations both play heavily on stereotypes.