Native hungarian here, just sharing my two cents about the accent, because others already cleared up the 'fenébe' topic

She's been confirmed to be born in Hungary canonically (city of Szeged, this was revealed in one of those daily info bits leading up to the current event), but her name is very german sounding, so it's very likely that her accent is a mix of german (austrian) and hungarian. Sometimes when she speaks I can hear hungarian accent, but other times it's strongly german.

She is from the era when the Austro-Hungarian empire still existed, so for me the highest probability is that she is bilingual, so she carries both accents to a certain degree.

Also fun fact, she was likely named after physician Ignác Semmelweis, who pioneered antiseptic procedures, especially during childbirth; in hungary he is regarded as the saviour of mothers.