Is it permissible for a foreign married woman, separated from her husband, to marry a Muslim man after she embraces Islam, or must she divorce her former husband? And does Islam supersede what came before it?

If a girl embraces Islam, her marriage to her first non-Muslim husband becomes void, and she must observe the iddah (waiting period). If her husband embraces Islam during her iddah, she returns to him with the original marriage contract. If he does not embrace Islam by the time her iddah ends, she is permitted to marry someone else, and her Muslim guardian (wali) or the Muslim judge (qadi) will arrange her marriage. This should be legally documented, and care should be taken to teach her the matters of her religion and guide her to marry a righteous man who will help her remain steadfast.