Best Friend Break Up

I am currently grieving a friendship that lasted 7 years. She and I were thick as thieves. Almost always on the same page and always had each others backs and were honest with each other when things were heavy.

Last year she got married and a few months later she got pregnant. This is when she started pushing me out. She had always told me that if she was mad at me, she would tell me... but she just starting pushing me out and I don't know why.

I'm not a mother, but I know pregnancy is hard. I've had a few friends who I've been around during their pregnancy and I've noticed 2 things:

1. It is different for everyone, but it is a lot of stress on the body and mind.

2. People have a tendency not to respect pregnant women's boundaries whether it's unwanted touching or inappropriate topics.

Seeing this through the years I wanted to make sure to be there for my best friend and also respect her boundaries. I'd ask how she was doing and she would get huffy at me like she didn't want to talk about it, so I still checked on her but not excessively. When I messaged her I wouldn't hear back for a few days. Then a few months later she started making passive aggressive comments to me about how our friend Maggie was the only one who checked on her everyday. I let it go and chalked it up to her struggling with her heightened emotions.

I also stopped getting invited to things except parties. At first I thought nothing of it. She would always talk about not wanting to do anything because she was tired. I'd still try to make plans with her and cater to her, but also not push her to do anything. We stopped seeing each other as much and I noticed she was still going out doing things with other friends. 

Then things started getting worse. Someone joked that if her baby pooped on them they would throw him in the trash, she started laughing. I said I just wanted to squish his cheeks and she gave me a death glare and said that people did that to her as a kid and that it hurt. I also caught her sister in law mocking me to her. When the SIL noticed, she tried to play it off. 

She also expressed constantly that she did not want anyone coming to the hospital when she was in labor. But recently I found out that Maggie went. She also talked about not wanting anyone around the baby for the first few months. I came to see him after he was born but didn't press her for more time because she was very hesitant about having people over. 

The break up fight happened on my birthday. She and her family came over and were being incredibly stand offish and rude, ignoring anyone outside of their group trying to talk to them. Then while she was in the room pumping, my other friends son hit her SIL in the face with a balloon. She told him to stop and he did. I told his mother what happened and she immediately apologized to the SIL, who accepted the apology but then proceeded to message my best friend in the other room talking about my other friend and her son. From how everything panned out after this, i believe the SIL lied about the situation to make it seem worse to my best friend because the SIL does not like me.

So then, even though my best friend was not in the room for any of this, she starts being weird and rude to my friends son. He has severe adhd and struggles with impulse control but he is a sweet kid. Then after his mom goes inside, my best friend starts bad mouthing this 7 year old boy and talking shit about him where he could hear. I was so shocked because she has never been like that and I had to walk away. 

A few minutes later she comes around the corner and asks me what's wrong and I tell her it bothered me to hear her talk about a kid like that. She immediately got defensive and kept saying she was trying to protect her niece and nephews. Thinks got a little heated and she wasn't listening to me and I finally snapped and asked how she was protecting her niece and nephews by talking shit about a child. She stormed out and we haven't spoken since but she has been posting things on fb directed at me, as well as dragging my name through the mud. A lot of people randomly stopped talking to me and I know a lot of them through her so I'm sure it's due to whatever she's started telling people.

This whole things is so against her character. I know she is struggling mentally but I also think that it isn't an excuse to treat people like dirt. 

any thoughts or insights? this has taken a toll on me mentally and I'd just like some perspective