I think both would look good on you.. personally though, I'd go for the 35, more bang for buck and especially if you can carry it off, you should do it !
I think the 30 looks just great on you. Don't be so self-conscious, enjoy that bag. Oh and enjoy your new Alma!! How exciting. One of LV's best designs IMO.
If you can pull off the 35 you're a lucky girl! I think it's a great bag, and even though the 30 looks great on you, the 35 is more bang for your buck!