On the good side, I'll bet it was easy to pull the trigger when they finally broke in.
You know... I was thinking. She was on the phone with the 911 operator (that had to be somewhat comforting) AND she had all that time to “think it out”. I mean she could mentally prepare herself to aim and fire. In no way am I saying she was as calm as a cucumber. I do think, however, the bit of time may have helped her. IMHO.