My MIL is a SNAKE!

Judy 🐰👓 • 🌞 24 years old, proud Navy wife. expecting our first baby in June 💙 👶🏽 IG@gls.xoxo
My husband and I have been married 2.5 years, we now live in Japan (thank god we are away from her poison). My MIL problem towards me began 1mo after we said our "I Do's", she invited to her bday one of his ex girlfriends to the dinner. (since their HS breakup she's been friends with her) after that I apologized for having left the restaurant but it only made things worse by making her believe I was going to let her step all over me. She now tells my husband she wants a sincere apology but even then she wouldn't know if she would make the effort to get along with me. She also said she wasn't going to accept my apology because she was "Soo hurt" when both my husband and I came to an agreement about leaving yet was blaming me for it. Let me add, we both felt uncomfortable sitting literally right next to his ex. Since then she has tried luring in ANOTHER one of his ex's while we have been in Japan who she so miraculously because friends with after we left CA. This insane woman has been communicating with a total of 3 of his ex's. She also tried feeding my husband bad lies about me that weren't true. She wants to make herself feel the victim by posting ridiculous lies about me on Facebook saying she hopes he divorces me, she has blocked me from Facebook and never acknowledges me when she calls him. He now keeps his communication with his mother to a very minimal and has been putting a distance between them. I told him many times before our baby planning that I wouldn't want to tell her until after 6months into my pregnancy because she has been pushing me away. The only way she will find out is if she notices my bump through a Facebook picture, not because we will be reaching her out and letting her know. Is that rude for me to do? I feel if we tell her we won't be congratulated anyways and she won't be happy to have her first grandchild. When would you tell her? Excuse me for the very long post.