I didn’t say it did. I wasn’t responding to someone saying she had Russian proficiency, but that she spoke a slavic language, though - she does because of her country of origin (a country which doesn’t exist anymore).
It’s not uncommon from people from places like the Balkans to have mastered multiple languages (probably less so now, for people who were born after the wars). Yugoslavians likely spoke Serbo-Croatian, Slovene, German, Albanian, and probably some Turkish or even Arabic to boot, to some degree, because of the history of the region as a cultural/ethnic/religious crossroads.
