I would assume that "Maharleah" is really Mahalia. I assume you are not an American, because that spelling will really confuse a lot of people in the USA, where we pronounce "r" strongly and would not think that a good representation of the sound "ma-HAH-lee-uh". :)
Zamora is a Spanish surname indicating one's ancestor came from the city called Zamora in northwestern Spain. According to Hanks & Hodges' A Dictionary of Surnames, the place name may have come from azemur, Arabic for "wild olive."
Most experts I've seen seem to think that Isabeau is simply an altered form of Isabelle.
My guess would be that the screenwriters of the film Attila just invented N'Kara, as I've never before seen the name of an ancient Hun written with an apostrophe. Of course, I'm not an expert on ancient Hun names, and you'd have to check books about them to see if there is anything similar historically.
As the following remark from this board in 2004 says, Denahi is probably just an alteration of Denali, the original name for Mt. McKinley in Alaska, though one would have to consult the screenwriters of the film to be 100% sure: