Peacekeeper novels (Tanya Huff)

Gunnery Sergeant Torin Kerr had been the very model of a Confederation Marine. But when she learned the truth about the war the Confederation was fighting, she left the military for good. But Torin could not walk away from preserving and protecting everything the Confederation represented. Instead, she drew together an elite corps of friends and allies to take on covert missions that the Justice Department and the Corps could not, or would not, officially...

Former space marine Torin Kerr returns for one final adventure to save the Confederation in the last book in the military science fiction Peacekeeper trilogy.
Warden Torin Kerr has put her past behind her and built a life away from the war and everything that meant. From the good, from the bad. From the heroics, from the betrayal. She's created a place and purpose for others like her, a way to use their training for the good of the Confederation....