She’s one of the most loved companions from prior games, she’s a drow and she’s a worshipper of Shar. Makes sense.
Isn't there's this thing about...
...her ending if she was romanced in Throne of Bhaal, where she is assassinated? Or am I misremembering things? I guess it could be retconned either way by resurrecting her since post-Spellplague a lot of dead characters were just brought back, and there could be a dialogue bit acknowledging the romance if the player wants it to be canon.