The two were Snatchers together, and Scabior was drawn to the young woman because of her devotion and promise to the job. Solara was drawn to Scabior because she detected that there was far more to him than met the eye. They grew closer by sharing the theory that the war would soon end, as well as training Solara.
However, the relationship is far from perfect- Scabior's greatest fear is that the insanity in his mind will make him kill Solara, being guilted by causing the same occurrence to a woman he had already loved.
Solara would give anything to know Scabior was loved.
Scabior would give anything to know Solara was safe.
Painfully adorable, isn't it?
Scabior proposed to Solara not long before his death, and the two were due to be wed once they were both free from the Snatchers.
Sadly, the ship was forced to die when Scabior went to the Battle of Hogwarts to earn his freedom, and died there. Solara was left behind to ensure her safety, and thus lived, carrying Scabior's unborn child.