Why does parvana tell nooria to write her mother a note?

Parvana asks Nooria to write their mother a note to keep her informed about their situation and reassure her. Since their mother is worried and struggling after being forced to stay at home, the note serves to maintain a connection and provide emotional support during a difficult time. By communicating with their mother, Parvana hopes to alleviate her anxiety and strengthen their family's bond despite the challenging circumstances they face.