I'm shorter than you (5'4") but I'm not petite. I have VERY broad shoulders, am straight up and down and have skinny hips and legs. I carry a 32 Kelly. I have both retourne and sellier. My favorite is my cocoan chevre de coromandel - it's a sellier. I can fit a LOT in this bag, but I'm not someone who carries water or an extra pair of shoes - if one does that, then a Birkin is a much better choice. My retourne is a vintage black box. I like the retourne in box as it is less formal. I'm dressed very casually most of the time.
I think a 32 moves on into "dressy casual" evenings better than a 35 does. I did try a 35 retourne and could have carried it when I was heavier (I've lost 68 pounds!), but to me the Kelly is such a classic, that I think when it gets big, it gets a bit "trendier" and that's not what I wanted.
I LOVE chevre! Mine is chevre souple so it's not a stiff bag at all. I have no trouble getting in and out of either one of my bags - very easy.
I hope you have multiple opportunities to try on a variety of sizes, both sellier and retourne, and multiple leathers. Take your time - it's a BIG purchase.