Banning My Mother From Seeing My Baby

So here's the story....
My mother is absolutely bat shit crazy . She sees a psychiatrist and is on all kinds of medicine, but it doesn't help . As far as I know , she's only been diagnosed with depression but I know that she has other mental issues , just not sure what . When I was a teenager, she threatened to kill me by telling me that she was going to slit my throat in my sleep . Two months ago before she stopped speaking to me , she called me a "selfish pig" because I was busy and didn't answer her text message right away . She hasn't spoken to my husband and I (for whatever reason ) in 2 months and doesn't know that I am pregnant . Honestly , since she hasn't spoken to me , I have been a lot less stressed . Well yesterday, out of the blue , she starts blowing our phones up with text messages threatening us and calling my husband all kinds of names and saying really hateful things to him that only a crazy person would say . My husband got all upset , as did I . My husband doesn't want me having the stress , since I am pregnant. He blocked her on his phone so that she can't call or text him anymore . I have been so upset over this and cannot get what she told my wonderful husband , out of my head. I have told my husband that after the baby is born , I do not want her around the baby unsupervised, the baby is not to go anywhere with her alone , I DO NOT want her in the delivery room, the baby cannot stay at her house and she cannot babysit. I don't want my child exposed to someone like that and mine and my husbands fear is that when our baby is older , she will put a lot of untrue things in his/her head and make him/her dislike us, because she's nuts like that . She's very jealous of everyone and everything and she sits on her ass all day and does nothing . She tried to collect disability because she doesn't want to work , but she couldn't, because they told her that nothing is physically wrong with her . We did a lot for her at one time , including paying her bills and getting her out of debt when we had our own to pay , buying food for her , putting gas in her vehicle , etc. she never thanked us. She is selfish, greedy and a narcissist. She plays the victim and constantly puts guilt trips on us. I don't want her around me , my home or my family . I told my husband that if I need to put a restraining order on her , for fear of my safety , then I will. Sorry so long , but I needed to get that off of my chest , as I have been super upset by this whole situation .
Additional info : I forgot to add that the reason for her contacting us yesterday was because my dad willed some things to me (I'm an only child) and she says that she wants them back . I am not giving those back , as my dad said in front of several whitnesses what he wanted me to have and those things mean a lot to me. 
She lives 45 minutes away from us and at one time wanted to move in with us! We kept telling her that she was not moving in with us or on our property . She was furious and I know that she still is . She is very controlling and the fact that she can't control me angers her. She starts arguments with people because she loves to argue . No one in my family likes her or associates with her anymore because she is so HATEFUL to everyone ! She curses people out and calls them all kinds of things and then expects them to be there for her when she needs and to drop everything that they are doing . She uses people up then spits them out . I actually had to delete my Facebook a while ago because we were friends on there and the statuses she would post were nuts and it was embarrassing me . 
My child may never know his/her grandmother, but that's ok , because I can't have that type of negativity around my baby. 
She was alone for Easter and Mother's Day , because she hasn't spoken to us so we did not go . I miss my dad so much ..he had a heart of gold and put up with her for 32 years . He was wonderful man who was miserable in his marriage , but stuck to his vows. She controlled all of the money and everything was in her name . She would give my dad an "allowance" every week . He had to go back to work after retirement to make ends meet , because she refused to work . My dad never complained , even though he suffered from a lot of medical issues and passed away from cancer. 
I am just so hurt and devastated by all of this . I don't show my emotions a lot , but my husband knows that I am hurting so badly . I told him that I don't have a mother who is supportive, helpful , loving , encouraging . She is none of those and I can't talk to her about anything because she can't hold a normal conversation . I get so upset when I go somewhere and I see others shopping with their mother or what not . It hurts because I don't have a relationship like that with my mother .