Correlation between petite women and c-section vs. vaginal birth?

So, my doctor told me very early on that I would have to have a c-section, not only because I have already had two, but also because of my petite stature and small body frame along with the position of my uterus and cervix. At the time I let it go and didn't push a VBAC because she is the doctor and Im not. But the closer I get the more I cant help thinking...what does my petite stature have to do with anything if I am having an average size baby? I know not every single petite girl out there has had to have a c-section...

So is there really any real correlation between body size and how you deliver???