Tides of Mars

When Ariel Janis is invited to the reading of a will, she was wondering how this woman had known her. She discovers the woman had been her biological mother, and that she had inherited far more than the vast corporate empire the woman had amassed. She had inherited a legacy that extended off world to an alien Empire. She discovers that she is the heir to the throne of a multi-star-spanning Empire that is in serious trouble. Not only are hostile aliens about to invade, the political structure of the Empire is, at best, teetering on the brink of collapse. Can she fight a civil war, and fend off the superior invaders bent on making humans a staple of their diet?