Oh wow, that's so difficult!! I have the 36 mm floral in silver and I love it. I am a big fan of the 36 size but you honestly can't go wrong with either one. (And the diamonds are so pretty on the meteorite!)
That 31mm is beautiful!. 36 is much more chunky when you have a smaller wrist, and I just don't feel that it will have the longevity of the 31mm or 28mm size. Of course if you plan on getting another Rolex in the future, then you'd be ok with either size for now. The pink one is beautiful as well.
The 31 meteorite isn't too busy to read- It was really difficult to capture the beauty of it in a photo. I thought I wanted the 36 pink wave dial, but in person it does look a bit too big on my wrist. I am leaning toward the 31 because it is really unique and it looks like a decent sized watch on my wrist. I've got both on hold and have to go back to try on again. Over at Rolex forums it's pretty close to a unanimous vote for the meteorite with a majority of posters being men. Only the women vote for the pink LOL!31 is a much better fit on your wrist. How about the readability of that meteorite with diamonds dial--rather busy? Is that a consideration? There's a pretty pink dial available in 31 too.