From Halopedia, the Halo wiki
Esme Guayte is a Lieutenant of the UNSC Navy. She served aboard the UNSC Black Widow.
Esme Guayte was raised on Earth. She attended the Academy at Mare Nubium on Luna.
In 2526, Esme was stationed aboard the UNSC Black Widow as part of Task Force Yama. Esme and the Black Widow were chosen to lead Sierra Force for an attack on Naraka in the Agni System.