Haha! I have her wearing nightingale armor too. Your characterisation of her is lovely. The facial structure is in your style while managing bear obvious similarities to Serana's face. I must say I love the hair; it is exactly how Serana's hair should look.
I could totally see this.'d be the one casting illusion spells everywhere. Not to mention there isn't an illusionist (unless the dragonborn plays as one) in the Nightingale triumvarate. Moto Bene, salute!