Board Thread:Spoilers!/@comment-26159109-20150928143524/@comment-1894786-20151114232343

Killian Jones wrote: Regina doesn't know everyone, but some people (myself included) theorize that the as the Caster of the curse she has some "abilities" related to the curse, such as She was trapped in that town with nothing to do for 18 years. I definitely think she checked in on every single person. That's why she knew instantly that Ingrid didn't belong. Also, she first thought Owen was August, so she didn't have the ability to recognize outsiders.
 * Recognizing outsiders (Kurt, Owen, Ingrid, Emma, August)
 * Also, we know that some cursed people don't get the new memories as soon as they arrive to the LWM. Prince Charming had zero new memories/personality/life, untill the situation needed him to have them, so the Curse gave these to him. Once magic comes to Storybrooke, Regina inherits this ability herself, making her able to use the Curse's magic to do the same thing for others like Belle (giving her the Lacey persona)