"My mother isn’t on Reddit to see me complaining so I am in fact leaving her alone."

Ok, cool! Got it: so you just like typing a lot of pretty intensely judgmental condescending stuff about your mother behind her back then?

Either way, my original partially comedically phrased comment to you is still the same then:

"Leave your mother alone!" Stop dissing her and judging her so much, and so harshly, about this issue, to her face, or cowardly behind her back as you chose to do.

(NOTE: Unless of course she was abusive to you--I don't know your family dynamic--in which case I would say, if she was abusive, then go for it: and dis her some more then!)

But otherwise... Just because she wanted to watch a funeral and was moved by it... You're so angry with her?

"She is grown."

I totally agree! She is grown. And thus she has a right to her feelings/emotions/interests, whether or not you approve of them.

As for you, and being "grown"...

Well, based upon how triggered you are by your mother's connection/innocent watching of this event that spoke to her on some level...

I'm not so sure about you yet!

"If you read the comments I’m talking about my sister..."

Actually: re-read your own comments!

Because none of this triggered reaction is about your sister, and rather has everything to do with your mother.