My MIL said I turned her son against her?

I’ve always got along fine with my MIL although I thought she was controlling and selfish I always kept that to myself and never said anything to anyone all the 10 years I’ve been with my husband. My husband and my MIL got in a huge fight and I mean more then a fight she did something and my husband said he is done with her and told her to never contact him again. My husband was 100% justified in this... I defended his mom and said that they just need to talk it out and she will realize what she did was wrong. And they should make peace instead of cutting her off for good.

Well next thing I know my phone has messages from my MIL saying that she knows it’s me who turned her son against her and a bunch of other stuff and then told me she hopes I lose my children one day just like I made her lose her son.

I was so upset I of course showed my husband the messages and well that was it from there he was completely done with her shit. And now So was I.

I felt dumb for defending her and trying to get my husband to mend their relationship. Funny how she jumped to conclusions and decided to attack the one person who was trying to help her.