Does a Christian wife fall under the category of disbelievers whom the Hadith has forbidden from inheriting, based on the Prophet’s (peace be upon him) saying: "A Muslim shall not inherit from a disbeliever, nor shall a disbeliever inherit from a Muslim"?

A Christian wife does not inherit from her Muslim husband, by scholarly consensus. The majority view is that a Muslim does not inherit from a disbeliever. The proof for the absence of mutual inheritance between Muslims and disbelievers is a hadith (definition) in the Two Sahihs. And the People of the Book are among the disbelievers, due to Allah Almighty's saying: "Those who disbelieved among the People of the Scripture and the polytheists would not have ceased [from disbelief] until there came to them the clear evidence." [Al-Bayyinah: 1].