Never a bridesmaid

First, today's post a bit of cheat because I am not wearing this out. I am wearing a tank top and very short shorts, for writing. Later, I'll throw on an A-line dress, which Style Underdog reminded me yesterday is key for hot weather.
I am going to a bridesmaid a few short weeks for a very lovely friend. I've never been one before, and I am hoping to do the job well. The bride wants a 50s vibe, but if you've noticed, I don't really have a 50s build. I wanted to a really light dress, because it's outside in the Chicago 'burbs, in early August (which is swamp like and powerfully sunny). She also wanted black and white, with a black dress. Jessphg did a great post on black summer dresses a while ago, so I ended up buying one of her "similar to" dresses. It was a $35 summer dress from Delias, that shop for girls aged 14-18. It had a full pleated skirt and a fitted bodice. There was also talk of getting a crinoline, for the '50s vibe.
Fast forward to today, when I got the pretty crinoline in the mail. Here it is:

From FireflyVintage. They upgraded my shipping for free!

I used some pins to adjust the height, threw on the dress, and voila- I realized that my long torso strikes again.

please ignore the fact that I look like I've been sweating in front of a computer all day.

The bodice is an oh-so-significant 1 1/2" inches from my natural waist. Since I am more than 1 1/2" above average height, I suppose this is to be expected. But the end result is I think I look thicker in the middle than I'm used to seeing myself. The bride said no to a colored sash, so I have a few options:
1) Buy or make fairly substantial (like 3") ribbon or similar fabric belt. I'd have to use some interfacing to make it more sturdy, and I'd lower the belt strings a bit to tie it under the bodice. Maybe some hook and eyes strategically place to avoid slippage (time to completion, including shopping for materials: 4-5 hours, maybe $5-$10 max
2) Figure out a way to lengthen the bodice. I'd have to take out the stitches holding the bodice to the skirt, hopefully without ruining those perfect bleats. Then I'd attach a 2 1/2 inch waist band made of similar materials (time to completion: 8-10 hours, maybe $12 cost).
3) Say "screw it" and decide that I look good enough, it's not my wedding, and as long as the bride doesn't mind (she got this picture forwarded to her), I can go back to writing.
Thoughts?