Divorcing one's wife for insulting one's mother

My wife insulted my mother for jealousy over my second wife. My second wife used to live with my mother. Initially my wife who lives with my mother phoned my other wife through my mother's phone and insulted her, as a result she called back to my mother's phone and insulted my mother badly. She used disgusting words when she was insulting my beloved mother.

What should be my reaction to this, shall I divorce her or not? Please advice me on this matter.