I'm going to tell my mom not to pursue a legal matter
Is there any reason why you want to do that?
The reason is that I don't want her to take legal action against me. She is using this to control me.
I know that a lawsuit can be a scary thing, but trying to manipulate your mother into not suing you will only make things worse. Leave your mother alone and let things settle down so that you can instead have a conversation and work things out.
This is really my shit and I will never let it go.
As I said before it's better to leave her alone and not manipulate her into doing something. Well, you can have an honest conversation about the matter with her but try not to control her.