How long have you been seeing her image?

I think if it keeps going on, then it is definitely something to bring up with the pdoc. Were you close to her when she was alive? If so, IDK, maybe your mind is trying to comfort you that she's OK? Do you see her when it's not very light or when there are objects around? I know sometimes my mind will make something out of an object and then when I get closer, it will be something completely mundane, like a weirdly shaped tree or something like that.