We have this little girl that shows up every spring and looks like she is 7 yrs. Old, she is wearing a bonnet and a blue dress. She talks to my daughter and invites her to her b-day party in the woods. My daughter who is 7 is the only who can see her. We have heard knocking on doors and a little girl crying, a little girl saying hello. Could this be a ghost and if so how do I find out?