My family is Jewish. My sister married a non-Jew in an “interfaith ceremony”. They divorced 6 years ago. She asked for a Get but since he is not Jewish, he laughed at the requirement for her to obtain. He has since remarried. She has now expressed interest in remarrying to a Jew. Is this permissible?
It is permitted and ideal for her to marry a Jew (though not a Kohen).
The marriage to a non-Jew is not valid in Torah law, and therefore no divorce is required.