But the child was shuttled away at night (from her sleep), deposited in a new place, her parents and brother must have exhibited some level of anxiety, she obviously would not be allowed to roam in the White House and if she opened the door to leave the living quarters, she would run into Secret Service and who knows who else (possibly armed with guns), and she is shut away from the TV. I don't know about anyone else, but as a child, that would have made me more curious than ever. She's disconnected from her surroundings, her friends, her electronics, maybe even her own cell phone. That would raise the level of curiosity and anxiety in a child, let alone anger if not being told the truth.
The mother should have had the opportunity to ease the child into the situation, and I don't see why the mother didn't make that time. She didn't have to hit the child over the head with a sledgehammer about the whole government getting killed. Better that a parent ease the child into the situation and assure her that she is safe, than risk the child learning it on her own. Keep her away from the TV? Pfft. There must be numerous TVs in the living quarters. Of course the child would turn one on. Even if they removed every TV, she just had to look out the window to see chaos, police, firearms, smoke, destruction.