Hello Friend, Good that you are seeking a help here. Behaviors with anger, frustration, argumental, irritation, Mood swing, hurtful speech etc are expression of stress or outburst of stress in mind or lifestyle.
Sometimes bodily condition like excess heat in body, PMS,
thyroid issues, acidity etc also can trigger and influence such stress.
As body and mind are interlinked it can affect each other.
Be positive. Just observe and analyze what's happening in personal and professional life. May be work related tension or relationship issues could be triggering such behavior.
She may need some counselling guidance to cope with such stress levels and control emotions over loved ones.
Be positive. She will be alright soon. Feel free reach me online for further evaluation and recommendation.