بسم الله الرحمن الرحيم
The male would lead the prayer and the adult members will stand in row behind him and then children and in case there is only one child he will stand in the row of adults and then the row of women should be arranged; the salah of all shall be valid.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.