Are you a stranger?

I took Hadley and Hudson to hobby lobby with me today so I could custom order a frame. I had to bribe Hadley with a toy to stand right by the cart so I could talk to the lady for a bit. A few minutes later I hear Hadley quietly ask a customer walking by, "Are you a stranger?" I turn around to hear her ask again because the lady did not hear her. After the lady (not so friendly, by the way) said no and walked off I asked Hadley why she asked her that. She said, "Because if she is a stranger then I cannot talk to her." So at least she listens to us even though she doesn't quite understand the concept...