Let's be honest: She is working this. Her makeup and hair are so perfect that I don't even miss a necklace, although a pop of color there might've been nifty. It's not a demerit that she skipped that, though. She had to know this was her night, and I think it shows a lot of maturity that she picked something that was classy without being showy, and which she'll be proud to look back on in ten years when she glances up at the framed photos on her home office wall/above the mantel/in her third downstairs half-bath.
In motion, when she turned sideways, there was a LOT of structure there that looked natural on a person that slim, but which also provided a wee security blanket just in case anybody decided to bring a fetus to the party. Just saying. WE do not think she looks in any way large; we are just responding to the Twitter speculation.