"The children are eating soup."
Translation:Děti jedí polévku.
It is only possible in a fairly limited number of situations where ARE EATING is strongly stressed and where the message is that they are indeed eating it or that they are eating it and not drinking it or something like that.
Since we do already accept "Polévku děti jedí." I will accept yours as well, but be sure to be aware of the disclaimer. It is NOT the normal word order.