This name has two different pronunciations. As a Polish name, it is "Yah-juh", rhyming with "
Raja".
However, it was the name of a character on "
Star Trek:
Deep Space
Nine" and she probably had babies named after her in the USA while that show was in its initial run between 1993 and 1999. There the character's name was pronounced "Jad-ZEE-uh", first syllable rhyming with
Chad or
Tad.
I think the writers on the show ran across the Polish name and thought it would be great for their alien Trill character, without knowing how it was pronounced in Poland. There was another character on the show named
Nerys, which is a Welsh name which I believe rhymes with "Ferris" in Wales, but on the show that was pronounced "neh-REESE".