All perfect praise be to Allah the Lord of the Worlds. May Allah`s peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Difference in religion is an obstacle to inheritance because, in Islam, inheritance has a religious particularity. Therefore, a non-Muslim can`t inherit a Muslim since the Messenger of Allah (PBUH) said: "A Muslim can`t inherit a non-Muslim and a non-Muslim can`t inherit a Muslim." {Agreed upon}.
It is stated: "Muslim scholars are agreed that a disbeliever can`t inherit a Muslim and, according to the majority of scholars from among the companions, their followers, and those who came after them, a Muslim can`t inherit a disbeliever." {Shareh An-Nawawi Ala Muslim, V.11:52}.
This same view is confirmed by Article (281/B) of the Jordan Personal Status Law (2019). It states: "Difference in religion is an obstacle to inheritance, so a non-Muslim can`t inherit a Muslim."
What counts, here, is that the deceased and the heirs must be following the same religion (Islam). Therefore, if the wife had embraced Islam before the death of her Muslim husband and the division of his estate, she can`t inherit him. Al-Shehab Ar-Ramli (May Allah have mercy on him) said: "If a disbeliever died and his pregnant wife embraced Islam and gave birth, then her baby can`t inherit because what counts, here, is that the heir and the deceased must be Muslim at the time of the death of the latter." {Nehayat Al-Muhtaj, V.6:27}.
However, it is permissible for the Muslim man who married a non-Muslim woman to make a bequest to her as long as it doesn`t exceed one third of his estate. He will receive the reward of charity if he intended that as an act of kindness to please Almighty Allah. And Allah The Almighty Knows Best.