Referenced from: Fatawa ‘Ulama-e-Hadith, Kitab al-Salah, Vol. 1, p. 186❖ Question
Is it Sunnah for a husband and wife to perform prayer in congregation together?❖ Answer
It is permissible for a husband and wife to pray in congregation. However, the wife must stand behind the husband, not beside him.(Reference: Fatawa Ghaznawiyyah, p. 47)
