I haven't tried many, but the only one I've heard good things about is Tuberose Indiana, I believe. I find Love in White and Love in Black to both be AWFUL.
Really, it would be better to know what your sister likes. What is her current perfume? Also, why are you set on it being a Creed fragrance? I'm no expert, but I think that their masculines are much better regarded than their feminines.