The Seven Brides-To-Be of Generalissimo Vlad — Victoria Goddard

A promise is a promise ... Portia MacArthur is possibly the best courier in the galaxy. Severely scarred from a training accident, she prefers the solitude of space to social interactions, especially ones involving her family. Vlad Millington, new Generalissimo of the Kinrod Syndicate, is a noted rake of galactic fame about to choose his bride. When Portia and Vlad were ten, she promised him she would be there on the day of his betrothal with a fleet of spaceships. Nothing -- not social disgust, not her brother's idiocy, not a mysterious interstellar predator, not even the black hole in the centre of the galaxy -- will stop her from keeping that promise. She just hopes Vlad's still worth it.