You would probably have no savings with Husband and 3 kids of that ages. You would require at least 2BHK flat.

2BHK - QAR 6000
Food and Grocery - QAR 2000 to QAR 2500
Transportation (by cab) will be anywhere near 1000 inside city per person. Better buy a car.

Not aware of schooling expenses. But you need to also consider the medical benefits, schooling allowance if provided by your employer.

Best of luck