Minor allegation case with harassment and false blame – need legal advice

I need legal advice regarding a sensitive situation. A minor girl came to a house voluntarily when no adults were present. Later, she left in panic when her mother  came and got injured after falling/jumping from height, resulting in a fracture. Now her family is blaming us completely and demanding money, along with repeated calls, threats, and mental harassment. We did not use any force or do anything wrong. We are now facing pressure and fear of false implication. Please advise what legal risk exists, how to protect ourselves, and whether we should file a complaint or wait for action from their side.