“Jewish” in America can mean simply one’s ethnicity and not necessarily a religious observance, and her ethnicity is not Jewish, since Jewish ethnicity is matrilineal. The non-Jewish reader of news means no disrespect by saying Ivanka converted her religion. Since her father has made an issue of his Christian heritage, to say she converted is a matter of factual reporting.
Where in the Bible does it say it’s a sin to mention conversion? Not doubting you; just curious. I seem to recall in the stories of the Jews’ return to Jerusalem to build the second Temple and restore the walls around the Temple, or possibly in the Book of Esther after she and Mordechai vanquished their tormentor, many gentiles from the surrounding areas adopted Judaism, but I can’t recall where I read it exactly.
A Jew is a Jew is a Jew is a Jew is a Jew is a Jew is a Jew.