I agree I would let her wander and if in the future you have a civil/calm conversation with W, tell her the truth. But if she is hurling accusations at you, don't respond. How are you doing otherwise?
Me 41 W 33 M 2013 Suspect A 11/15 Confirm A 1/16 She moved out 2/14/16 Stepson 13 Stepson 16
