MORE SPOILERS FOR TFA
Well, it seems I may have been a bit hasty. Like I said, on my second viewing I noticed the screaming children since I knew she was approaching Anakin’s lightsaber. However, the “leaked script” from a few days ago that contained information subsequently confirmed by Pablo Hidalgo describes the scene as a little girl crying, implying it to be Rey. That makes sense, though I couldn’t say for sure without seeing the film again… I suppose it won’t be too hard to justify going to the theater again.
Here’s a snippet. I’d like to hear your thoughts.

Rey is heartsick, but she turns as she hears the sound of a young girl in anguish, crying. She follows the sound into the castle, turning so she can’t see that Finn has looked back at her one last time.
INT. MAZ’ CASTLE - BASEMENT CORRIDOR - DAY
Rey steps down into the basement corridor. BB-8 follows
her. Walking carefully and confused, she is not sure why she’s down here. She can hear the echoing sounds of a young girl crying. She heads down the hall… to the very end, where there is a door. It is almost as if a SOULFUL VIBRATION draws her closer. She looks at the door lock – AND THE
DOOR OPENS.