It does not though. You are 100% correct that reasonable people will consider the same thing you are. Any jury will also have this same fact pointed out to them.
That said, there are ways to test this. Has anyone thought their life was in danger and then killed someone in what they thought was self defense, only to find out they misunderstood the situation?
The answer is yes, and if you want I can give you examples.
What you seem to be stuck on is that she was not actually in her house, but, as I have tried to explain, that does not ultimately matter in her fear of safety.
One side is going to argue gross negligence and say she should have picked up on her mistakes and that it was her decisions that lead to the event. This is currently my side.
The other side will be that people make mistakes and she reasonably thought she was at her house, and that someone had broken into it. Upon being confronted with the intruder she reacted and shot the man.
That 2nd part only works if there was not an argument. If there was, and there are hints that there might have been, then it starts breaking that argument. That's because she was given even more ques to realize.
But, the argument for sure will be that she thought she was at her residence and that she thought she was confronting someone that had broken into her apartment.