Frimmlova is apparently just "daughter of Frimml", a Slavic patronymic borne by female members of the family. That's why it may appear to be two different surnames merging into one, the daughters would be Frimmlova, and the sons just Frimml. The name appears to be Austrian, hence it's spread east throughout the old Austro-Hungarian empire and the variant Frimml/Frimmlova. The root is not Fri-, but a grade of Fram- "forward", which has a wide range of derivatives, with meanings ranging from "righteous" "brave", "vigorous", "profitable". Fremmel is probably cognate, rather than a variant.
This message was edited by the author on November 11, 2020 at 8:10 AM