And I think the mother is wise to be selective about whom she shares this information with.
While I contend that most people do not have enough faith in mental health professionals, there are so few good doctors and/or therapists in this world. Telling the wrong provider that your kid is "seeing ghosts" could have lasting repercussions.
I think the caregivers would do well to at least sage out the child's room, (and the rest of the house) perhaps get it cleared out by a good energy worker. Saging probably won't do anything to change whether or not the child continues to see apparitions, but it might protect the girl from negative ones.
Finally, I hate to be alarmist, but I think they should (obviously) be on guard for indicators of emotionally unhealthy or, god forbid, self-destructive behavior. The child could be legitimately psychic, sure, or there could be another explanation for what she's going through. Either way, seeing ghosts could be stressing her out quite a bit. Something to keep an eye on.
Edited to add: You could try steering the family toward Celebration's YouTube videos for energy clearing. Anonymous and free and can be used by anyone. Might provide them all with more balance:
http://www.youtube.com/watch?v=ECecI8_Eb_s&feature=channel