I realize this thread was made a while ago but here.
Okay, I don't really agree with some of the answers you got and I'm not going to start a debate but you're not prettier just because you're thin. The only reason people believe that is because we come from a society where the majority was thinner (mostly likely because there was a lack of food in poverty ridden Europe) in some countries the bigger you are the better, it's a sign of power and good health (in Africa where the thin are sick and dying).
I would suggest
EASIEST: Go to Starlets and Harlets and pick up some of their stuff from the "Voluptuous Sizes" section.
dresses plus size
Otherwise
:
1. you teach them how to sew (Pro: They could start making whatever they wanted. Con: It takes a while to learn to make presentable and neat clothing)
2. Get a customized one (Pro: You could get exactly what you want. Con: It could cost you a shitload!)
3. **Look for Gothic (a lot of goth clothes come in bigger sizes and cross over into a lolita look) and styled clothes or Gothic Victorian or just normal Victorian because while the STYLE originates from Japan, the actually style of the clothing itself is a product of the Victorian era. (Pro: may be a complete solution Con: May solve nothing because it's not what you want. I say: Worth a try)
4. You could mix and match. Take 1 corset top from torrid, maybe all black or black and white or whatever. Go to a dancewear shop or online at some type of ballet something and get a tutu. All that under a pea coat and fishnets and one of those pretty intricate hair clips maybe some gloves. Also you can check plus size lingerie sites, that often have nice stuff that can be turned lolita. (hit or miss thing I might have missed completely there)