just a thought on your idea of when someone is too old for imaginary friends.. completely normal adults do have imaginary friends.. some of the most amazing inventions have come out of people holding what if conversations with their self and their imaginary friends.

I still have an imaginary friend I talk to, I know the difference between having a hallucination and having an imaginary friend. I have experienced both. my imaginary friend is someone that comes to me when ever I need to talk to someone and my wife and therapist are busy.

My therapist has an imaginary friend she talks to sometimes. he friend has been with her since she was 4 yrs old and they grew up together.

I know many other adults who have imaginary friends to bounce ideas off of, talk to in times of stress and upheaval of life.

what is an imaginary friend...well some people their imaginary friend is their higher power, for others its their deceased someone, for others its their own image, for others its an animal, plant, or other person creation...

in my culture there are bears, wolves, birds, and other visionary/ imaginary friends that lead the person on vision quests and help guide them through their life.

my point is your belief and culture may say theres some age limit on how long or when its appropriate to have an imaginary friend but not all people and cultures do.

this may or may not be getting to the point of being too old for this child in question to have an invisible friend. only the child, the childs parent and the childs treatment providers can say when this child is too old to have this person she has named God be her invisable friend.