django unchained - Why Broomhilda rather than Brunhilda?

First of all, she is indeed spelled Broomhilda (with an "M") both in the credits and throughout the movie. I think it's only Schultz who calls her Brunhilda due to his habits. I just understood that as a parody of the original name, emphasizing her status as a slave, since she's supposed to carry a broom when cleaning up behind her masters, something along those lines.

I just thought it has always been her name. But given that her original plantation owners were Germans it may also be that her original name was indeed Brunhilda and the parody name was only developed later by other plantation owners, overseers, or co-slaves.

But it might also have another meaning, given that comic-strip and Tarantino's fondness for the 70s.