Baby question?

my almost 4 month old granddaughter is living with us. her mother was neglecting her & CYS is involved. she is a very pleasant baby. smiles & talks alot. not real words, just sounds. alot of gooing. anyway, her mother came for a visit. the baby cried for her. she did not know her. the mother is non emotional with her. does not talk to her & is not loving at all. the baby kept stairing at my girlfriend. amanda then tried to take her from us. there was alot of loud talking going on & the baby was in the middle of all the caous. the police were called & the mother was told to leave. my issue now is the baby keep stairing at us. very deep stairs. she is not talking at all now. what could be wrong? the episode happened 4 days ago. the baby has not been right since. is this normal. could she have been affected by what was going on? any help with this situation will be greatly appreciated.