Aaaah, there's a Bulgarian connection in far more creative things than the assassination of the pope =o).
Anyways, Ratka is a (for the lack of better term) misspelled variant of Radka, which is a short form of Radostina,
Radoslava,
Radomila or any other name starting with
Rad- "joy".
> "misspelled" is not quite the right term, as the "d" in Radka is pronounced as "t". Yet, no literate Bulgarian beyond the age of 8 would spell Radka as Ratka, unless they care more for the right pronunciation than for the spelling. Would a Greek pronounce a clear "d" in Radka?
Or Ratka's parents may have been of Bulgarian origin but not quite speaking the language and might have directly transliterated what they hear into Greek.