Your paternal grandfather married

Q: Layla is a mother and Salma is her daughter. Khalid and `Aly are two brothers. Khalid got married to Layla and `Aly got married to Salma. Layla had another daughter that was called Yusra while Salma had a son who was called Hasan.My question is whether it is permissible for Hasan to marry Yusra bearing in mind that she is regarded as his cousin and maternal aunt?

A: If the reality is what is mentioned in the question, it is Haram (prohibited) for Hasan to marry Yusra because the latter is his maternal aunt and Allah (Glorified be He) says, Forbidden to you (for marriage) are: your mothers, your daughters, your sisters, your father’s sisters, your mother’s sisters May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.