From David Mack's Desperate Hours: Mack painted her as a Human born on Illyria (which has its own alien species, per Enterprise), which sorta conflicts with her being an "Earth woman". Although Greg Cox in "Child of Two Worlds" has her annoyed at being confused with an Earther, again and again (Not Earth, Illyria, she thought irritably. How many times do I have to explain that?). She's constantly described as an Illyrian and not human (correct me if I'm wrong!) in the Cox books I have access to, which were all written after Damage, but Mack's retcon seems a suitable fix for that situation.