I feel like I should let my mother rot away in her home.
Why would you want your mother to rot away in her home?
There is literally nothing I can do for her. She's getting old, she has made up her mind.
Parents can be burdensome sometimes, but when they get older it's our responsibility to take care of them. If you let your mother rot away in her home, you'll likely regret it and feel ashamed when she passes. Try to help her as much as you can while you still have her.
It's her life, not mine. I feel nothing when it comes to her, she was a terrible mother.
It doesn't matter if she was terrible, you can be the type of amazing person that you always wished she was while you grew up. It is always important to take care of your parents whenever you can-- no matter how you felt about them.