Assalaamu alaykum. Please calculate the inheritance according to the following information:
- Does the deceased have male relatives who are entitled to inherit: (A son) Number 1 (A husband)
- Additional information: This is a second marriage. The husband is a Brit who converted to Islam for the purpose of marriage only.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

If a woman dies and leaves behind a husband and a son and she did not leave any other heir – like a father, or a mother, or a grandfather, or a grandmother, or a daughter – then her husband gets one-quarter of the inheritance due to the existence of children, as Allah says (what means): {But if they have a child, for you is one fourth of what they leave, after any bequest they [may have] made or debt...} [Quran 4:12]

The remainder will be given to her son by virtue of Ta’seeb (by virtue of having a paternal relation with the deceased and not having an allotted share, so they get what is left after the allotted shares have been distributed), as the Prophet said, “Give the prescribed share of inheritance to those who are eligible for it and the remainder [of it] is for the nearest male blood relative.” [Al-Bukhaari and Muslim]

Therefore, the inheritance should be divided into four shares, the husband gets one share and the son gets three shares.

The husband inherits as long as he is a Muslim. He is only prevented from the inheritance if he apostates, and he is not prevented from it just because he embraced Islam for the purpose of marriage.

Allah knows best.