A girl's paternal half-brother marrying her maternal half-brother's niece
Is it permissible for a woman's paternal stepbrother to marry the daughter of her maternal stepbrother?
If the reality regarding the family relationship between the concerned parties is exactly as what is mentioned in the question, there will be no impediment that may invalidate the marriage of the woman's paternal stepbrother to the daughter of her maternal stepbrother. Since there is no text to ban this, permissibility; which is the general ruling; should apply. (Part No. 18; Page No. 374) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.