I'll leave comments on how the drugs were smuggled to others, who can say it better.
The woman should be punished but I would not charge her with murder. That is virtue signaling. She is not a drug dealer. She is a drug user. She brought drugs in and used them with other inmates. It sounds like she almost died too. She should be punished for smuggling drugs into prison but it takes two to tango. She did not force the other inmates to take the drugs. I feel the same way about the way Matthew Perry is treated like some saint while his personal assistant who facilitated his drug use is vilified. Drug addicts will find ways to get drugs. They are to blame for their own deaths.