I just wanna say, Salina is awesome! She always answers all of my questions.. I e-mailed her and this is what she has to say about the pumps:
"I have the Memhis pumps in a size ___, which would be the size I would normally take. However; I have to admit, the memphis are cut rather small in front and bigger in the back of the shoes. I think maybe you should size up by half size and if its to big, you can always add a insert to your shoes."