First of all: This probably belongs in the lore-forum.

Second: Once you've completed all four Shadowbringers jobquestlines you'll get a last quest that will tell you more about her, who she is, what shes doing on the First and maybe even where she is right now... I dont want to spoil any of that right now but if you dont want to play through it yourself, you can probably find a transcript of the quest in question somewhere. Its aclled "Shadow Walk with Me" - heres a random video I found from someone doing the quest: https://www.youtube.com/watch?v=TPnpVEIApqI (obvious spoilers ahead for anyone who hasnt completed the quest!)