Once again, I need your assistance

I think it's safe to say that all of you out there, collectively, wear pants with an elastic band fewer times in a month than I do in a week. That is to say, you are all more fashion-forward than me. So I need your help. PLEASE.
I finally bought a dress for the military ball that's coming up (in, ya know, 2.5ish weeks), and while we're still not 100% sure that we're even going, I need to be prepared in the off-chance that we do go.

This is the dress I bought.

I know. Let's all be jealous at how un-pregnant this little twig looks modeling a "maternity" dress. Perhaps dreams of possibly looking so skinny whilst harboring a baby in my chub-riddled midsection might have sold me on this particular dress. It mentioned something about being dry-clean only, which to me, means "fancy fabric." I possibly own two things that come with such a tag, and they are worn about as often as you think I wear them. (Ahem. Not that much.)

But once I received the dress in the mail, it kind of squeals, "I'm a maxi-dress from Old Navy!" (Do not tell me that you saw this coming.) I mean, I can totally get away with wearing it since it's floor-length and no one will be actively grabbing the fabric and asking me what it's made of (and if they do, I will absolutely tell them to "quit touching my baby!" and huff off like a crazy person, which should stop the touching altogether).

My question for you lovely fashionistas is this: hair? shoes? necklace? I gotta dress up this covert maxi-dress and make it look "formal." I obviously plan on wearing some sort of flats.. possibly my Old Navy sandals (oh the irony) that look identical to this? (WITH A PEDICURE FOR SURE)

I am not one of those girls that has amassed some super-spectacular shoe collection from my single days, so this falls under my "fancy shoe" category. Holler if I am incorrect in this categorization.

I am almost completely decided that I will look like I put some time and effort into this "look" if I do my hair up. Or rather, someone else will do my hair up, because it took me visiting a "hair salon" (I use those words loosely) approximately two weeks after previously having my hair cut/mangled/chopped to be told that my hair on the back of my head had basically been mutilated. My fashion-forward husband was oblivious to this travesty as well, so at least he wasn't embarrassed to be seen with me. HOWEVER. I have never had a good experience with a hair dresser (and I mean NEVER) and I think it has something to do with my curly hair. Apparently curly hair isn't considered need-to-know-material in beauty school since the majority of America has been bestowed with straight, manageable locks. So I will need to bring in a life-size poster with some picture plastered on it so that the person attempting to do my hair has an idea of what I would prefer to look like. Please help me choose. Or suggest something different altogether if I am destined to be embarrassed by any or all of these looks.

I especially like her necklace in the last picture. That would be the final piece of this here puzzle- finding a nice, chunky piece of jewelry to make my cheap shoes and dress look, well, less cheap.

Or do I need something simpler and less chunky?

THE DECISIONS. I am ill-equipped to make them.