1. You can size sterling silver, but only a silversmith who knows what they are doing will work with SS, but yes it can be done and I believe two of our board jewelers will do it (Images and Winfield's).

2. She is totally wrong about being able to tell a real sapphire by it's color only....(especially by some salesperson in JCPenneys, which I assume means she is not a gemologist).
Real sapphires come in very very dark blue, however they are not usually as valuable as the brighter blue sapphires. It takes several tests by someone who knows what they are doing to tell an earthmined sapphire from a good lab sapphire.... If she was only going on color, then she is only guessing - IMHO.

3. AND, that was more than rude to have said that to you!!!!!