Isabel Mayfair is a British national who married an American in pursuit of happiness. She is now settled in New York City. While her husband worked for the State Department in Washington D.C., she pursued a position as an assistant attorney general in Washington, and then as an assistant to Attorney General Holder.
Her marriage to Holder ended rather sourly, with the secretary of state publicly accusing her of straying. In light of all that happened, Isabel Mayfair decided to follow her own path in life and wed her American-born spouse, Joel Grigori. Isabel Mayfair has never mentioned being anything but a dual national, even while conceiving her second child. This could be because she is simply not comfortable discussing her origins, and her sudden marriage to a foreigner raises questions about the nature of her marital status.
In any case, the public record does not reveal whether Isabel Mayfair’s original marriage to Joel was legal or not. The new marriage was however recognized by the US Government, and she obtained US citizenship in spite of her conviction for fraud, after serving time in jail for her first offense. The only way to know is to read the judgment of the Federal Court which convicted and imprisoned her. In that case, she was not allowed to enter the country, but is now able to live and work in the USA.