Kris Longknife: Defender (Kris Longknife Series Book 11)

Kris Longknife is back in the good graces of the brass—and to demonstrate that, they've promoted her to Admiral.  Now her mission is to find the home base of the space pirates who are plaguing the fringes of the galaxy.
 
But no mission is ever simple when your name is Longknife. And this time the complications range from the military to the personal, as Kris finds herself—reluctantly—having to make some command decisions about her future...