amanda taylor , 24 , charged with first-degree murder in stabbing of her former father-in-law charles taylor .
taylor blamed 59-year-old victim for introducing her late husband , rex taylor , to drugs at age 15 .
rex taylor committed suicide by hanging last august , leaving amanda alone with two children .
ms taylor allegedly committed stabbing with friend sean ball , but then turned on him as the two were fleeing police .
she has confessed to the crimes on facebook and instagram .
friend mariah roebuck said taylor had checked herself into hospital in late march but was released three days before her father-in-law 's killing .