According to her story, she did not KNOW anyone was in the apartment until she discovered him.
But your point is valid--if you KNOW there's an invader, you avoid engagement and use the phone.
With luck, you can get to a spot from which you can defend the entire family and not have engaged.
Yep, you're right. And that was my point. You don't know if someone is in the house, but they may become aware that you are walking about, looking for the "noise."
Personally, the few times I had nothing for self-defense and aware that someone was about outside, I damn near panicked. (Even a little goofball knocking on our doors at night not too long ago just about sent me in a tizzy.) After getting handguns, I have walked around the house if I hear noises.
However, watching that video recently of a burglar shooting the owner who was checking up on noises about gave me a heart attack - how many times have I done that myself? So now there are extra precautions, like locked windows and such, so if someone tries to get in the house in the first place, it will, hopefully, be pretty obvious to me.
So darn many scenarios a person has to prepare for. Trying to figure out the "what ifs" now instead of later.