The Roads of Heaven Trilogy

Five-Twelfths of Heaven - Book I of The Roads of HeavenIn a space-faring civilization where a single woman is increasingly disenfranchised, the star pilot Silence Leigh is defrauded from her inheritance by a greedy competitor. Forced to ally with two men, Silence is dragged into a deadly political struggle, and is tantalized by the hints of the legendary Earth, as well as the dread and the glory of Magi's power.
Her dreams of having her own ship and of escape from the Hegemony's oppressions take on new direction and focus when she joins the crew of "The Sun-Treader."Silence in Solitude - Book II of The Roads of HeavenIn Five-Twelfths of Heaven, Silence Leigh discovered that she was not only unusual, as a female pilot, but that impossible thing, a female magus. Her unique abilities make her the only person capable of reaching Earth, humanity's original home, now sealed behind a mysterious barrier - but first she must learn to use her new-found talents.
As the Hegemon's men close in on her and her husbands and teacher, she must make a dangerous bargain: undertake an impossible rescue mission in exchange for a vital map. If she succeeds, she may be able to save Earth. If she fails.The Empress of Earth - Book III of The Roads of HeavenFollowing "Five-Twelfths of Heaven" and "Silence in Solitude", this is the third and concluding novel in the Silence Leigh series.
Silence Leigh now faces the ultimate test of her skills as a pilot and of her powers as a sage. Silence has finally wangled a deal with the Hegemony to use their gear to help them find the lost star roads to Earth. This comes at a price, though, as the credit for this will go to the leader of the Hegemony's family, so that one of his relatives can inherit his position, given that he has no children.
The roads are not lost by accident, there is an active group of planets trying to block access to Earth, setting up a final conflict.