May be some time many people were heavily broken inside, but they don't mention their feeling in front of others. Then that kind of incident take place, just ask your mom what happened and what's the matter i'm sure she was mentally tortured by someone and didn't say anything to him. So, she bursted on you because you were the only one at that time to face her angered or to release the stress of her. But it's wrong as it impacts bad on child health May she get over with it in time.