What is the ruling on a brother meeting his female cousins (daughters of his maternal uncle) in a public place, while adhering to Sharia guidelines, and how can he maintain ties of kinship with them if such a meeting is impermissible, and does people's ill-opinion matter?

The aforementioned meeting is not permissible due to the elements of temptation it contains, such as joking and playing cards. This is an unlawful mixing of genders. Maintaining kinship ties (silat al-rahim) can be achieved without this mixing that includes what contravenes the Sharia, specifically by exchanging greetings and inquiring about their well-being. Imam Ahmad said: "Kindness and greetings." And in the hadith: "Moisten your kinship ties, even if only with a greeting." It is recommended to maintain ties with relatives to the best of your ability, based on the Almighty's saying: {And give the relative his due} (Quran 17:26). However, this must be without seclusion if they are not mahrams, and while she adheres to the legal hijab.