So I was able to sneak a ring out of her jewelery box and take it to the jeweler to get an accurate size. The only dilemma now is that this particular ring she can wear on her right ring finger but it is very tight. The ring measured in at 5.25. She is left handed. What size do you think I should order the E-ring in? I am really trying to avoid any kind of resizing because it is going to be platinum and have diamonds on the shank. Thanks for all the help.