I can give you pretty generic advice: no matter where you go, have them measure her. Cup size differs by store, so your daughter might fit into some Cs or DDs (which would make it even harder, trust me, been there). I've had luck in Boston Store/JC Penny/Macy's at a 32G (relatively small for my bust, so I'm fairly certain they could have her size) after asking several staff members for help in searching. Going online at stores just to check for prices/availability/if they even carry those sizes helps up, but always try on before buying. Allure was recommended to me, though I don't know if it's a chain store. And there is no such thing as a final form. I grew six sizes in a year (D, DD, DDD, DDDD/E, F, G), and it's normal to fluctuate with weight loss/gain. It's recommended to get resized with every 10 pounds gained/lost, and as an adult I was told to get resized at min. twice a year because they will change. Anyway, keep in mind unless you go to Victoria's Secret or a highly over-advertised place (which, if you buy a bra there, you end up paying for the bra plus advertising and not quality) that you tend to get what you pay for... meaning, $20 for busty girls can only be found in a clearance rack on your luckiest day (which I haven't ever had), and more likely you'll find a decent bra for $40 plus. I think Kohls goes to D for 30 and 32 (last time I checked), so if that's true, that would be the best place for an affordable option. If she gets a bit bigger, I'd recommend getting a quality bra. I neglected that and it was a horrible mistake... I thought I'd worry about sagging at 50 plus, but my reality was that I started really noticing at age 19 and it was obvious to everyone at age 20. Even though cheap is ideal, support helps with back pain, preventing sagging, posture. I do get it. I am so frugal (minimum wage kinda gal), and it cost me, which is why I now forget the tags and swipe my card for my bras (pretty much the only expense I do that to).