from what she said, you two share an unusually close relationship between M-F friends. Hmm, married bestie on the backburner/backup?
I'm probably a boob man, although i'm also an ass and tiny waist man and face man lol. My wife has implants, a DD, but she was in the porn industry. My #1 SB has fake D. Both have amazingly large areolae, which i find really sexy, and their nipples get erect most of the time, which i also love.
Women in my experience either get bolt ons for work or self-esteem. In this case, it sounds like they're for your friend's self-esteem. Does she want to look better in a dress or actually pull random men's eyes? or just your eyes lol? Sometimes a pointed question is more than face value lol.
I presume you've seen her in a bikini, what is your opinion on the relative proportion of the B cup to her body? You said she's gorgeous "just the way she is." But are you a boob man? Sounds like probably not based on your SB comments.
Because i'm a boob man and somewhat a professional (don't ask) i'd probably go way into detail with your friend. FOr you, either way tell her she's perfect... especially if you want a shot at the prize one day lol.