Who is the guardian for a girl in marriage after her father's death, and is the guardianship of her 17-year-old younger brother valid, or the guardianship of her paternal uncle despite the severed relationship and his refusal of guardianship?

If the brother reaches maturity, he has more right to give his sister in marriage than the paternal uncle. The brother is given precedence over the paternal uncle in the authority to solemnize a marriage. Efforts must be made to mend relations among relatives and remove estrangement, especially with the paternal uncle, for his status is great; as the Prophet, peace and blessings be upon him, said: "A man’s paternal uncle is like his father’s twin."