I bought these for my mom and followed the guidelines based on previous reviews.  It turned out that, in my mom's case, getting her actual size was the way to go.  After I got her actual size (7.5), she still didn't really like the shoe.  She felt like the strap was pinching.  I'm only hoping it's not too late to take them back.

The shoe itself is cute and seems versatile; however, if you are overweight (as my mom is), and your feet swell, you may consider a show that doesn't have the overstrap.