You know your friend's personality better than we - I suggest that you choose to compliment her, not necessarily the image we jointly declare "best."
That said, all the images are good - although number three doesn't really work for me - her hand seems caught awkwardly. I agree that the first is probably the most glamorous one. Number two is possibly most reflective, But I'd probably choose number five, the 3/4 length, as it shows not only a beatiful woman, but conveys elegance, poise and grace, IMO. But those are my impressions - again, you know her, we don't.
Nice work. Thanks for sharing.
"Keeping shooting will do more for the excellence of your photography than most any camera will!" JimmyD, PGS Extraordinaire.