WitchesWitches can be a tough mob to kill.
As mentioned above, witches cannot do two things at once. If you have any cows around your mansion, I suggest you use their milk as a precaution to fall back on. But beware, for one is an easy target when one is
busy drinking; make sure the witch stays occupied, or get out of firing range. If possible, circle the witch (the same technique used against skeletons). Good luck!