How big(cup size) is normal for a petite frame? (photo)

Unfortunately, you have not told us your bra
size just your cup size. If you are 32 or 34 each 100 cc’s of implant
corresponds to 1 cup size change.If you
are 36 or 38 each 200 cc’s of implant corresponds to 1 cup size change.From this, you can compute the volume
required to achieve your desired goal.I
always recommend small round textured silicone gel implants placed
retro-pectoral since they look and feel more natural, are more stable, less
likely to ripple or have complications needing revision.Implant profile is irrelevant in the
retro-pectoral position since the muscle compresses it.Best Wishes,Gary Horndeski, M.D.

Ideally you need
an in house consultation with a Board Certified Plastic Surgeon.  There are various factors and specific
measurements the surgeon takes into consideration when determining implant size
for patients.  Once you have been assessed
by the surgeon you can try on sizers which will help give you a visual of what
size you would like to be. Many surgeons also offer digital imaging.  There is no “standard” size given for patients;
it is all based individually. In the
end, your result should be beautiful natural looking breasts.

Thank you for the question and picture.  There is no "normal" cup size for petite patients. There is also no reliable correlation between specific breast implant size and resulting cup size. Generally speaking, the best online advice I can give to ladies who are considering  breast augmentation surgery (regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.

2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural”  or “big C cup”  etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup  size may also be inaccurate.
 The use of computer imaging technology may also be very helpful during this communication process.

3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery.
I hope this and the attached link (dedicated to petite patients) help.