I don't know if it's your style at all, but I have this WCM Adjustable Toggle Belt that I wear at my low hip and it's QUITE adjustable. Extrapolating from my waist measurements, I think the S could fit as small as a 20" waist.
Because of the design, there's no excess overhang in the front.
It's a little spendy at $58 (full price) but it seems fairly well made to me. Two notes if you're interested:
* the buckle dips into that V shape due to the way they have it styled...I *am* wearing it that way, but it will also sit in line with the belt when made tighter
* I bought mine at a B&M Nordstrom and it's black patent all the way around -- I'm not sure what's going on with that leopard-y back view but you may want to check with a CS rep if ordering online
http://tinyurl.com/WCM-AdjustableBelt
FYI, not sure what your other measurements are, but the Alterations Needed site + forum focuses exclusively on petite sizing issues -- mostly on the short + superslim side. (the 4'11/000 type of thing).
Even if you just wear a smaller shoe/belt/bra you can pick up advice on which brands and styles are likely to work.
http://www.alterationsneeded.com/
