Interesting idea, not sure if it makes much sense translated to more than a gathered skirt dress [basically just a vest with a gathered skirt tacked on] and a plain T shirt.
My body SHAPE would be E, but then she goes adrift and says choose your shape by your bust size, which would be S [hourglass] Hourglass I ain't!
So I would have to start with the S [in other words, FBA done, big whoop] and then still grade out to the [probably] E waist and hip.
I do this anyway, so not tempted.
I also found the cutesy Disney style illustrations WAY off track for adult clothes.