Nearly there :)

Yes because the hip goes down to the knees go with Thighs and exclude buttock. Now you are down to adjusting the joint parameters. Start by having Vicki in the zero pose then work on one parameter at a time. You'll most likely have to increase the size of all the spherical fall off zones to take in the extra size of the dress. Also check the Vicki soften hip morph. The default setting is "1" you may need to zero it.