Darlington girl, I would just describe yourself as "curvaceous" or "voluptuous" - that's what I do. I'm a size 16 (sometimes 18
) trying to get down to a 14 so wouldn't want to put myself in the BBW category (not that I think there's anything wrong with being described as a BBW!). I know some think of a size 14 (and even 12) as curvy, but I'm of a "certain age" and can remember when a size 12/14 was considered slim (especially a 12).
Cassie, I don't think you need worry that clients will expect a slim modelesque type if you don't describe yourself as a BBW. They should be able to judge from looking at your website and I personally wouldn't put you in the BBW category (that's not to say you aren't a Beautiful Woman!). Everyone seems to have a different view of what a BBW is - perhaps the guys who go for BBWs would be the best ones to answer this.