The importance of niqaab

I want to ask a question on the importance of niqaab. I belong to a Pakhtoon family and we usually put a veil on our face whenever we go outside. My two cousins each of fifteen years came for study to our house. I told my mom that I will make niqaab from them but she got angry and said that you will not get any proposal due to your extra fundamental nature. She's a single parent so she is worried. I have failed to convince her. Whenever me and my cousins confront each other, I put a side of my dupata on my face. I am doing my best and the rest is up to Allah. Mum said do this all after marriage according to the will of your husband and do hijab only in front of your male cousins not niqaab. What can I do? I am very confused. Please guide me.