Hey ladies, I could use some help this is a long story but I need to vent

SO from the beginning my husbands grandmother never liked me she called me a whore and said I screwed every man I knew so he took my side cussed her out and didn’t talk to her for awhile. So months went by things was fine my husband got into my family’s business and started working with my step dad, she didn’t like that so she called dfacs on my 10 year old diabetic brother saying he’s not on medicine he don’t go to school and my family sold drugs. None of this true he takes his medicine is home schooled and they don’t do drugs. Now me and my husband is pregnant and she doesn’t like that at all she told everyone we knew i had to have fertility shots and no such thing . My husband posted a add on fb advertising work she didn’t like that and made him take that down. She called defacs again and now my mom has to go back he can’t see the evil in her I told her he called cuz she’s the only one that calls defac and he says no it’s not she wouldn’t do that. It makes me mad he can’t see how she is she talks sweet to him and she’s not ! What should I do whAt should i tell him? It makes me so mad he can’t see it