Clingy MIL.. Need advice desperately

I’m not sure if this is the right group to post this in , but I’m being induced Wednesday due to medical reasons. Well my MIL is not okay with one of the 3 rules we have set for visitation . It’s that we aren’t doing hospital visitors until the day after he is born . This is my first child and a lot will be going on in the first 24hours my family thinks it’s a good idea to hold off until the next day so they don’t see it as an issue. However my MIL is PISSED she wants to be there as soon as he pops out and isn’t okay with waiting until the next day . She’s stressing my husband and I out with it and she’s complaining and telling everyone that we aren’t letting her meet him. I’m just not sure what to do . There is no way I’m changing my mind on that rule , but my husband is trying to make me cave in so she will shut up (it isn’t happening) I’m just not sure how to handle this politely and I love her so I don’t want to be rude , but I’m getting tired of it. (Also I know no matter what she will show up at the hospital , if I tell the nurse can they keep her from coming in the room? )