What can I do about my wide ribcage and narrow hips? (photos)

Dear GhostDoll,
based on your photos, you look like a good candidate for a BBL. Liposuction of your abdomen, back and flanks should give you more curves and hourglass shape and fat transfer to buttocks should give you more projection. I would suggest you to consult a board-certified plastic surgeon because only after a thorough examination you will get more information and recommendations.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Your question had us all expecting to see a photo of the female version of the Incredible Hulk. Clearly this is not the case. Your proportions are well within normal limits and are even what some women strive for. Leave well enough alone. 

your rib cage is normal, proportionate and appropriate for your body height and size.  You do not need physical intervention at all.  Perhaps there are other forms of intervention that could benefit you.  I suggest excepting your body the way it is.  For people who truly do have a flaring rib cage rib removal has been done though it is not recommended by me nor most plastic surgeons.  Best, Mats Hagstrom MD