God, I can't even begin to express it how much I hate it when I see the made-up word 'Tsarina' in English-languaged literature. There is NO such word in Russian and has never been, no matter what your Russian language teacher or
this lame Wiki article say. The word you were looking for is 'Tsaritsa' - ruling wife of 'Tsar' which was derived from 'Ceasar'. Grrrr...