Almost cried over your post. I know you mean well, but your friend was kind enough to send you pics, and your impression is.. her boobs are wrong!

And since you guys haven't even seemed to talked about bras, you don't know if she's happy with what she has. Maybe she is. Maybe it is comfortable for her. And yea, based on that the subject hasn't come up, I do think she would feel really hurt if you went buying her a bra. It's like saying, sorry, but how you dress is simply not good enough for me.

If you really want to do this, it's better to give her a gift card to a place that have a wide range of bras but maybe one or two other things as well to choose from. That way she can if she like, go there and have a real fitting, and if not wanting a bra, choose another gift.