In-laws 😒 RANT/advice!

Kayla • I have one daughter and on the way is my wonderful son!!!
A while ago I was on Facebook and seen the my real sister was being kind of nasty to our mom (she is bipolar) and I had just seen a lot of negativity. So I posted a status about how it was ridiculous and all that bla bla. I did not mention names at all. My sister in law and myself were pregnant at the same time, her mom tagged her and I in some stupid post about some sort of wrap for your belly to help with back pain, she wanted our thought on it, and She was just bluntly rude about it. I thought it was a great idea ha. But my sister in law saw my post and ASSumed it was about her! So she posted a very catty post about me and I was really offended so I unfriended her because she is just negative all the time!!! And what pisses me off is she had her mom ask me what it was about but didn't have the lady balls to clear it up with me herself. So later on she realized that we weren't friends anymore and apparently that really pissed them both off.... So now I am childish because I didn't want to deal with it. Maybe I am! But she just recently had her daughter and now when I have questions her mom has to ask if it's okay for me to know! 
It since has put a block in mine and my husbands relationship because when his mom calls him he has to either have the phone on speaker or is really high volume our neighbors could hear! And I can hear her talking all kinds of rude things about me. And I NOT ONCE have heard him try and defend me. But if it were switched around I would definitely defend my husband against my sister and mom because when you're married, that's just what you do... Or so I thought. 
I should let it go and I am trying but HORMONES!!