My 14 year old has started talking to an AI companion app for hours a day and I genuinely do not know if I should be worried

My daughter is 14. About two months ago she started using one of the AI companion apps, I will not name it but it is one of the well-known ones. At first it seemed harmless, she said it helped her process things she found hard to talk about with people she knew. She is introverted and I understood the appeal.

Now she is on it for two to three hours a day. She has given the AI a name, a personality, a backstory. She talks about it the way she used to talk about friends. Her actual friendships have gotten less active over the same period.

I have read the horror stories online and I do not want to catastrophise. But I also do not want to dismiss something that seems like it might be replacing rather than supplementing real human connection. What does the actual research say about this, not the anecdotes in either direction?