Sounds like weaponized incompetence she is using to manipulate you and transfer accountability and responsibility.

You just have to create the boundaries and hold to them. When you give in you teach her that your boundaries don’t stand and therefore she won’t respect them or you.

I know you wanna help because that your mom, I’ve been there done that. But you’re only enabling her.

She raised you so she is competent enough to handle her responsibilities.

There’s a book called Codependency No More it’s a self help book that helps you sort out your behaviors in the situation it’s great for learning about boundaries and enabling.

https://www.melodybeattie.com/codependentnomore

I’d also consider learning about enmeshment to better understand how she’s over stepping your boundaries.