Blue shift : the second species trilogy, book one / Jane O'Reilly.

2187: Earth is cold, dead and divided. The rich hide away while the rest will do anything to survive. Humanity have only one hope: reaching a habitable planet. But getting there means travelling in large numbers through alien-held space, something that's almost impossible. Yet for some, fighting their way through space is just a way of life... Jinnifer Blue is a rich girl on the run. An expert pilot, she apprehends criminals on behalf of the government and keeps her illegal genetic modifications a closely guarded secret. But when a particularly dangerous job goes south, leaving her stranded on a prison ship with one of the most ruthless criminals in the galaxy, Jinn realises that the rich and the powerful are hiding more than she'd ever guessed.

Also issued in electronic version.