In Fury Born
Set about 1,000 years in the future, mankind has spread to occupy 1,800 worlds with an average of ~1 billion population each.  After fratricidal wars, mankind has been forced to unify in the face of the Rishathan, an aggressive alien civilisation.  This is the story of Alicia DeVries, from the time she is about 14 until age 30.  She chooses a military career, first in the Marines, then she is selected for the crack Cadre, the Emperor’s personal liege corps.  There are several well-told action situations as she moves along in her career, first in the Marines then in the Cadre.  Then at about age 25, she resigns her commission in bitterness over what she considers a soft attitude of the Empire’s authorities toward a fellow officer who betrayed her battalion into a Rishathan trap.

She joins her parents, brother and sister and other family members in a homestead on a frontier planet.  Five years on, a band of pirates attacks their planet and brutally kill most of the 30,000 inhabitants, including all her family members.  Alicia survives and launches a vendetta to avenge her family.  The author, surprisingly and convincingly, has her teamed up with one of the 3 Furies from Greek mythology and a state-of-the-art artificial intelligence-run space warship.  Great adventures ensue as the three of them pursue Alicia’s desire for vengeance, which she finally overcomes, at the same time as the enemy, with the aid of the Fury and the AI.
 
In addition to being an enjoyable science fiction adventure, the story is refreshingly free of any improper behaviour by any of the protagonists.  More, a very positive portrait of Alicia’s family is presented, with all rejoicing when her mother has a 3rd child more than 10 years after her second.  A Christian setting is revealed when the christening of the new baby is mentioned. There is, moreover, a positive portrayal of the virtues of loyalty, toughness, friendship, etc. 

But it is not “preachy”, but is rather a cracking good story, a page-turner.
Science Fiction, Vendetta, Fiction, Fiction, science fiction, general
David Weber