Thanks, everyone! This is definitely a keeper, and I will send back the other 2 sizes. I am going bra and underwear shopping this afternoon. I have a bra that will work but I feel like getting a new one. And the underwear situation... I still have not solved it. I am sending the Soma ones back because while there are no panty lines as advertised, there is still that dreaded waistband line which is actually the problem. The laser-cut (CK and Uniqlo) ones that I bought earlier will work in a pinch but they tend to bunch up at the sides and require some adjusting. That may be the best option though - what I really need is laser cut Vanishing edge (Soma, are you listening?).

ETA: Sveta, you are right. It's weird but the petite is actually longer than regular. Nordies' website even states that petite length is 50" while regular is 49.5". Funny, but it works for me because I am not really petite height anyway.