Pear

You decide your Gwen should be flat but making it up for the amount of weight her bottom will be carrying. You might think to yourself someone with her body type carrying around that extra weight might be too much for her. All the time Ben in the show made fun of how big her butt is he would have been right 110 % of the time.

As the proportion will be big due to how the company design the modified bodies to be a bit exaggerated to make sure your bot isn't entirely on model. If you wanted her exactly from the show you would have kept her like that instead of giving her a plastic ass that could be recycle into a couple cases of bottles, maybe cause a celebrity to be jealous upon seeing a "girl" like Gwen carry around that weight.

Hopefully from the description she wearing some large pants as her petite sized jeans would be tearing past those white denims, but the service would supply Gwen with optimal clothing when arriving with her fabric stretchers.