A good combination would have been the light and the gun. Look first, shoot later.

A better tactic might have been to hold your gun ready in the bedroom and yell out "Who the hell is out there? I've got a gun!" instead of trying to "surprise" the "burglar" (which would probably shock a real burglar into shooting if he was armed). Your sister would have yelled back, after getting her heart restarted. She certainly wouldn't have burst into your bedroom without saying anything. A real burglar, who probably (like your sister) would have thought you weren't home, would, 9 times out of 10, have fled instead of attacking. If not, well, there's still the gun. Of course, easy for me to say. Hindsight is always 20-20. Glad nothing bad happened.

Why was she rummaging around in the dark?