is the paragraph grammatically correct 
Children may quarrel all the time , drawing the elders into fray. The neighbour's son may pick a flower or a fruit from your garden and an argument (a) may erupt. Again, he may throw his ball (b) at   your window pane damaging it. These are not unnatural so far as the younger one is concerned , but it is for the elders to (c)watch them with equanimity.
 

Children may quarrel all the time , drawing the elders into fray. The neighbour's son may pick a flower or a fruit from your garden and an argument (a) may erupt. Again, he may throw his ball (b) at   your window pane damaging it. These are not unnatural so far as the younger one is concerned , but it is for the elders to (c)watch them with equanimity.

Options a) and b) are correct. For c), the better word for 'watch' would be 'view'.