Marked for Vengeance by Susan Hayes

She thought she was too old for adventure… until it blew up her ship.

Protecting her client while they cruised around the galaxy was easy work—at least until all hell broke loose. Now Loris is stuck on a hostile planet with poisonous flora, dangerous fauna, and a cocky-as-hell alien with big horns, broad shoulders, and an ego the size of a planet.
She needs to do her job. He’s decided she needs him. The longer they’re together, the more she wonders if he might be right…or if she’s losing her mind as well as her heart.