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
(..) What else? The Stormcrows rode off last night. men. Sellswords. Loyal to nothing but gold. We still have a hard march to Winterfell and we won't be marching anywhere in this weather. And? (..)2015 TvShow: Game of Thrones Title: The Gift Season: 5 Episode 7
(..) I was when I saw you? You've made me very happy. Our scouts report that Stannis Baratheon rides for Winterfell. He's a respected commander. His troops are loyal and battle-tested. He's hired thousands of foreign sellswords to bolster his army. But this storm is a stroke of luck for us northerners. (..)2015 TvShow: Game of Thrones Title: The Gift Season: 5 Episode 7