Theory of little girl?

So why did she not talk, why did she disappear? I have several ideas lets see if you agree or if you have a different reasons.

1. She did not speak Hebrew (I thought this throughout the movie, could of been like the Asian woman)

2. She was deaf

3. She was a figment of the woman's imagination as was the police officer and the photographer.

4. My dad suggested she ws silent becasue she suffered a trauma. He says sometimes trauma makes you silent. Eek scary thought.