I've viewed the video and I do see grief. I can only explain my feelings by telling you all that, had I been in her position, I just may have done what she did.
See, I'm the sort of person who, when disaster strikes, doesn't get emotional in the traditional sense. I'm the one who does what has to be done while others are wringing their hands and can't deal with practicalities.
A good example would be when my sister's cat fell from the beams into a triangular area in our basement. The poor thing was petrified and caterwalling. My husband was running around like a maniac, piling tools on the bed. My sister and niece were crying hysterically. They kept saying the cat would die because it had been declawed.
Me? I checked the closet wall area, the bathroom area, and the bedroom area for electrical service. Two walls had switches/outlets. I chose the third wall, behind the door in the bathroom, pointed to a hammer, and told my husband to break a hole in the wall, as gently as possible. Hole made, dusty cat rescued, emergency over. I then left the room and then the emotions hit me.
I'm asked by friends to "help" at funerals because of this quirk in my personality. I calm the grieving, act as hostess, and smooth things over. After the event, when I am alone, THEN I break down.
SH could be such a person as I. She's trained to be calm, cool, and collected as a nurse, ready to handle emergencies.
At this point, I have no clue as to "whodunit" and am anxious to see an arrest or arrests. If there's a lot of DNA, I'm sure test results won't be instantaneous.
I hate the down time between the sensational crime and the arrest.