Late Mum Ghost Picture

Sally Pitt sent us several strange pictures taken with a cell phone camera. One of the images has an unexplainable green bar at the bottom of it and a woman with a necklace in the rest of the picture. There was no one in the room. Sally believes it could be her late mum:

"These were taken on my sisters mobile of my halloween decorated frontrom. The picture with the green at bottom we think is my late mum. You can see a necklace round her neck."

Who is the lady they captured in the empty room while photographing Halloween decorations.  Is it a ghost picture of their late mum?  You decide...