The Girl would have been able to find Edmund anywhere, if someone had blindfolded her and told her to find him then she could have. Of course, the Girl could find anyone if she needed to and she could do a lot more than just that. She hadn't been surprised by The Just's invitation, because she was very difficult to surprise, but she certainly wasn't used to the kind of attention he had given her. He was the first person in her lifetime to give her a name without permission, and she liked it.
She walked into the park and straight over to where he was sitting and she waited a moment for him to notice her. Her clothes were a little old fashioned for a girl that looked like she was in her early teens, and she certainly wouldn't have looked out of place in a BBC Dickens adaptation.