In that kind of situation, it's always difficult to tell whether there was actually a ghost, or if your going crazy, or if it's just the weed...

The best thing to do is just decide not to worry about the little girl unless she bothers you, and if she does, maybe offer her a bowl.

When I'm high, or really tired, or sometimes under no special circumstance, I occasionally see flickers of movement out of the corner of my eye, although they rarely take shape. Sometimes when I'm alone in my house at night, I swear I can hear ghosts, because I perceive alot of inexplicable noises.

IMHO, best thing to do is accept it and move on.