Good for that little girl in the vid..

My understanding of US/Brit law is that a householder is only entitled to use lethal force IF they feel they or their family are being seriously threatened.
For example in this picture the burglars seem to be unarmed, so if she blew their heads off in Britain, she'd be arrested and the cops/lawyers would pin an "unlawful killing" rap on her.
Luckily, the Brit people are far more sensible than the politically-correct police and judicial system, so a jury would probably find her not guilty..