
So in other words, she knows she may be at fault...
Most likely. However, it should be noted that, under the axiom that a motivated prosecutor can indict anybody for something, she might figure better safe than sorry.
For example, maybe her attorneys told her that just admitting she knew he had the drugs in her house might be enough for an overzealous prosecutor to slap a accessory to possession charge on her. Or maybe the DA would try to argue that, by not calling for an ambulance, she committed "criminally negligent homocide" or something.