Now retired from an Exodus Republic, Inc. "cleaning service" she was very fond of after it was aggressively edged out by a competitor.
[She worked for an off book private military contractor which was taken out by a competitor, or possibly a client]
She recently arrived on Earth to enjoy a quiet retirement.
[She decided to hide out in the last place anyone would look for her]
She and Prof. Benjamin Syren met in a museum and bonded over cultural antiquities after she mistook him for a docent and asked a bunch of questions about the artifact he was examining. This lead to her helping him out around this drafty castle.
[old habits die hard]