Honestly it's a no-brainer, the US (and any other country including Canada for that matter) would shoot down a hijacked commercial plane with american children aboard if the government had reasons to believe that the hijackers were going to crash it into a building, government organization, nuclear power plant etc. Similarly the government will bomb a house with American children if it's the only way to get rid of dangerous terrorists planning to kill tens of thousands of americans.
Of course american kids have no reason to be in a house in Iraq, Gaza or another hostile area and if the house is in the US (or Canada) I am sure the military and the FBI can easily find much better ways to handle the situation and neutralize the terrorists without hurting the children.