Today, actors also change their names to align with the rules of the Screen Actors Guild, which is why the actress we know as Emma Stone is actually Emily Stone.
So if you happen to meet her somewhere, I guess feel free to call her Emily or Emma.
Since the beginning, some people would change their name if they thought their given name might make them sound less appealing.
She responds to Emma but it sounds like if she could just go back to being Emily Stone all the time, she would do so.