There were people that she could kill and wanted to kill, but it was still too much for her to give her enough reasons to kill each person.
There were times when she still had to go back to refer to her code when it came to making certain decisions.
There were many times when she could have done many things, but she knew that she should not take things that far, so the code was especially important during those times.
It did help her to control herself in the way she acted, especially when it came to reducing the number of people she would have to kill, even if she had reasons she could give herself for wanting or needing to take the life of another.
The first reason behind it all was that she wanted to reduce the number of lives of humans she would take to avoid being tainted by too much unneeded bloodshed, especially if some of that bloodshed could be avoided and would not be needed.
