What size shoe is my girlfriend in "christian louboutin pumps"?

i researched her closet, she is 7 1/2 in Tory Burch, Nine West. She is size 7 in Kenneth Cole and Size 8 in Steven by Steve Madden and Report. I want to make sure she gets the right size in the christian louboutin pumps im buying her...please help a confused guy out.