Answer:
Sybil Mira
Step-by-step explanation:
In the first volume of The Lunar Chronicles series titled Cinder and written by Marissa Meyer. In the novel series, it was revealed that Sybil Mira is Queen Levana's ambassador on Earth.
This is evident in the fact that she was the head thaumaturge of Levana and the ambassador of Luna to the Eastern Commonwealth. She has a personal guard known to be Jacin Clay