Should I tell my MIL that I’m pregnant?

So I can’t write the entire story but to sum it up, she has never liked me and 5 years into the marriage with her son she still feels the same. She has bashed me many times ok Facebook and when my husband tries to ask her why she doesn’t want to get along with me her response is “I’m tired son, I don’t have time for this”.

We didn’t talk to her for 4 1/2 years and suddenly she went crazy and called my husband at work asking him that she wants to talk to him again so here we are 8 months later and now I’m pregnant and due next month.

My husband wanted to tell his side of the family during the second trimester but it just didn’t happen and now he says he doesn’t want to anymore.

What should I do? Should I tell her or just keep our baby a secret?

EDIT: Just wanted to add more info now that I’m not at work lol. She lives 2 hours away from us so there is no chance of running into her at all. No one besides my family and him know about the pregnancy. His sisters are in the dark about it too and I want to tell them since it’s the first grand baby for both sides of the family. I’m open to her knowing but due to how she has treated me I do have my reservations about it but I want my husband happy in the end no matter what happens.

He is her firstborn and only son so I know she has the right to be protective and wanting the best for her son but wouldn’t it be better for all of us to be a family United and have peace among us. She refuses to add me on Facebook saying she doesn’t want to be my friend. But if she knows about my baby I know for a fact that she will be posting about the baby and etc. I just feel like as the mother of the baby I should be included more but it doesn’t seem to be that way for me.