Sassinak by Anne McCaffrey

The first in the Planet Pirates series, this science fiction yarn offers a vivid universe inhabited by cardboard citizens. Sassinak, the heroine and the only developed character, steps straight from a formula: When she is 12, pirates raid her native colony, enslaving her and g murdering her family. Abe, a fellow captive, befriends her and, when they are emancipated by Fleet (the military), becomes her guardian until he is slain in a barroom brawl. Intelligent and daring, Sass joins Fleet, seeking vengeance on her enemies. She becomes the classic fictional commander: a loner whose entire life is subsumed by the military.