Need some advice

My mother is absolutely crazy and has hurt me and my husband so much in the past with her verbal and emotional abuse. She’s told me husband everything under the sun , cursed him, used him (used us both, really ) and even took things as far as going up to one of his co workers and telling him to tell my husband to “kiss her ass.” The co worker reported that she did not say this in a joking way ...now mind you she had no idea who this guy was! She walked up to his vehicle and tapped on his window and when he rolled it down , she told him that. I am beginning to become very nervous about my son being around her ..my husband and I have already said that once our son Is born she is not to babysit , take him anywhere or he alone with him....however , i have seen the way that she talks to kids ..she tells them things like “Your mom and dad are crazy” and quite frankly I’m afraid that she will try to turn our son against us , because that’s the kind of person that she is. No one in my family speaks to her because she is a nasty mouthed person who curses people and tells them crazy crap for NO REASON! My husband is a good , hard working man and has never done anything but to help her when she would call crying that she couldn’t pay her bills because her lazy ass doesn’t want to work . She started all of this after we got married. She text me husband this morning and said to him “"Does your police chief have a big ass mouth and us ugly with messed up and hair and is black? " like wtf ! I try to keep my cool but I’m to the point where I’m getting enough and I really don’t want my child or family around her . She’s always the “victim” and everything is everyone else’s fault and she loves to put on a pity party . My dad passed away earlier this year so I do my best to not be mean because she is all alone because she’s run every one off. With the holidays coming up it’s going to be tough . She makes things so miserable for every one . I have tried to cut ties with her but it didn’t work. I’m just sick of her disrespecting me and my husband ! She lives 45 minutes away from us so I don’t see her often but it’s still close enough and I hate it . She tries to tell us how we should run our life and our household ...telling us that we need a guest bedroom for when she wants to come over ....saying that she wants to put a mobile home on our 5 acre property and that we need to let her . 45 minutes is too close to her much less having her in my back yard! I’m just fed up!