This unfortunately happens from time to time. I have a female that went rogue on her mate and killed him, this is after being with each other for over 3 years. You know how women can be.
In all seriousness, what you can try is to keep them separated for a week or so (the sump good because they can't see each other) then after a week or so, you can reintroduce the male to the female using a clear container. If she tries to attack him, then your female is crazy.