That is a hard question. What is chubby to you, may not be to others. What you think is BBW, is considered chubby to others. It is all relative. I will say that I think more bigger, average, and chubby woman should sell their panties. I think some feel that because they are not the skinny minni model type, that they won’t have buyers looking to purchases their wears. I believe there is a market for everyone and selling should be fun for the seller and desirable for the buyer.
I personally don’t know anyone but I would think you could find something on the member pages here on PH, plus the galleries will give you a good idea of size.
Good luck in your search.