Mother-in-law from hell

Long story short my fiance mother was mad at her son and put me in the middle of it..

She left a voicemail on his phone about my 3 kids I had before we got together and his 2 kids with another woman. So she starts talking bout both of our kids saying they ugly motherfuckers and what really got me not wanting nothing to do with her, she told his daughter that was raped by her mother boyfriend she needed to been rape.. So am I wrong for not wanting her to have nothing to do with our unborn child which is due in June?