She has provided the company with many years of 'loyal' service.
She has remained/stayed 'loyal to' her old friends.
has served 'loyally' for many years
(..) - Are you still a wanted man, Toby? - Look, George, I didn't know. I... - You pick ed the wrong side. No, you've got to believe me. George, please. I am loyal. I... I am loyal. Don't... Don't... Don't send me back. Please, George. Don't send me back. (..)2011 Tinker Tailor Soldier Spy