My brother's children were raised with my family and they all eat with us. Their ages range between 16 and 18 years, including the girls. The girls do not observe Hijab in the presence of my sons. What is the ruling on this?
Your daughters should observe Hijab in the presence of their male cousins, as any of your brother's sons is marriageable to any of your daughters. Likewise, your brother's daughters should observe Hijab in the presence of your sons. Having been raised together in your house is not an excuse (for not observing Hijab). (Part No. 17; Page No. 426) May Allah grant us success. May peace and blessings be upon our Prophet, his family and Companions.