Distribution of inheritance if a woman passed away without any Muslim heirs besides her husband

Q: Please could you state the Islamic shares on the following scenario:

A Muslim female passed away. She was a revert Muslim and left behind
A Muslim husband
Her late brothers daughter who is a Christian
Her late brothers son who has children and all are Christians.

She does not have any children. Kindly state the Islamic shares of inheritance in this case.

Selling half niqaabs

Q: Is it permissible to sell half niqaabs where eyebrows and forehead are exposed just to encourage sisters in their journey of covering the face ? (because a lot of times in the beginning it's hard for sisters to take a full niqaab).

Witnesses being present when taking consent from the girl at home before the nikaah

Q: In my country, before the actual nikaah, the qadhi goes to the bride's house to get her signature. Some people insist that there should be 2 witnesses there and some say no since this is not an actual nikaah but just to confirm that the bride has given her permission.

What is the ruling here? Should there be 2 witnesses when the bride gives her approval at her house and they have to be present in the nikaah to confirm that OR the mere statement of a wali during the nikaah (that my daughter has given her approval) is taken to be sufficient without the involvement of any witness (to confirm the above)?