Has anyone considered that maybe she was planning on robbing not just them, but others in the complex? Since she had worked there, she was familiar with the property, and knew which places had children.
She would assume that there would be lots of toys and maybe video games, etc. She could rob them and then sell the things she took. Maybe she was not expecting anyone to be home and when Jonathan was there she had to do something to cover for herself and in a panic Jonathan was killed or severally injured. Just a thought.
Not what LE seemed to imply during the press conference.