Normally I support cutting toxic people out of your life. I still do. But it’s a bit more tricky when it comes to family, including in laws. All you can do is try to focus on control and concern. The whole story is very concerning. Your in-law is acting like a emotional vampire and trying to manipulate you. You can’t control her and you can’t control how she will feel. Since you can’t control it, you should limit the amount of concern you give to it. Just try to stay calm and make sure you are being fair and stand steady where you draw the line. I hope it gets better.