That poor baby.
If she did die from some type of drug overdose, i don't think it was on purpose. She was dealing with A LOT of major stress right now - the death of her son, probably going through postpartum depression, and dealing with 2 ongoing lawsuits (one concerning the paternity of her baby and the other one dealing with the estate of her late husband). She may have just over medicated herself in trying to cope with everything.