JonnyQ, i agree with Homer Jay...i'm sure Petra didn't have a reduction. She is like 99 percent of generous boobed women who, in their late teens and early twenties, have whopping great boobs, afterwards they lose their fullness and plumpness. Those women often lose weight also which aides in the reduction of size and mass. You look at Petra's photos over the last few years and there is a gradual loss. In her case her overall proportions, very small waist and back still make for an awesome combo.
BTW, JonnyQ, love your avatar...where can i see it full size?