Not hers alone. She would have needed a cast of at least two dozen co-conspirators to carry it out. Remember she was on an airplane when Foster was killed. But as soon as she touched down, she started barking orders from Little Rock to DC to clean out Foster's WH office.
Don't know exactly how you would define "big kill," but recall that there had been a number of "Arkancides" before the Clintons reached Washington.
Bengahzi is her latest, IMO.
Big Kill = Washington Kill