As a former speechwriter, I can tell you with certainty that she didn't write it herself. I can also say that, whoever wrote it, there's no excuse for lifting an entire section from a speech given by Michelle Obama, even if it supposedly only amounted to "58 words" (the word count given by Newt Gingrich on Fox News this morning). "58 words" of someone else's speech is 58 words too many.
So I ask again, who wrote Melania's speech? And was larding it with a passage from a Michelle speech a function of the speechwriter's laziness and/or incompetence, or a blatant act of sabotage?
The person who wrote the thing deserves to be fired. Period.