So you found a good source saying that her *legal name* in the U.S. is/was Melania Knauss? Because I have looked this year and not found one.
Until we find such a source, I don't see how we can operate under anything other than the assumption that "Melania Knauss" is a stage name, as reported by The Washington Post and others, and that her legal name is still Melanija (Knavs) Trump.
Her English display name should, of course, be Melania Trump. I'm sure that Oton Zagorc would agree to that.
Her birth surname is Knavs and will remain so even if she changes her surname. But a changed surname IMO doesn't belong into the "Birth Surname" field.
Likewise her first name at birth was Melanija. As she prefers to call herself Melania Knavs I put this name in the "Also Knows As" field. If you need to translate it in English then it should probably be Melanie because Melania is actually latin.
I don't really see the need to translate Melanija into Melania. It's not as if the first form is unrecognisable to an english speaker. We in Slovenia don't generally translate foreign names (Uošington, Njujork, Džon, Klinton) except if a name is entrenched in the language. For example, the capital of Austria Wien has been known as Dunaj for centuries (and in Croatian it is Beč)
Whatever, she now has both English and Slovenian names.
Facts You Didn’t Know About Melania Trump https://www.heraldweekly.com/facts-you-didnt-know-about-melania-tru...