Some of the memes you referenced do seem "cringe" to me, but people have different senses of humor. I'm not sure what the issue is with someone posting memes they personally find funny.
If you disagree with the point that the memes are making, that's different, but can you give an example of something in one of the memes she posted that you thought was invalid reasoning? You called her content "dark arts tactics" and said:
"It feels like it is trying to convince me of something rather than make me smarter about something. It feels like it is trying to convey feelings at me rather than facts."
but you've only explained how it's making you feel instead of what message it's conveying.
If you look over all possible worlds, then asking "did the coin come up Heads or Tails" as if there's only one answer is incoherent. If you look over all possible worlds, there's a ~100% chance the coin comes up as Heads in at least one world, and a ~100% chance the coin comes up as Tails in at least one world.
But from the perspective of a particular observer, the question they're trying to answer is a question of indexical uncertainty - out of all the observers in their situation, how many of them are in Heads-worlds, and how many of them are in Tails-worlds? It's true that there are equally as many Heads-worlds as Tails-worlds - but 2/3 of observers are in the latter worlds.
Or to put it another way - suppose you put 10 people in one house, and 20 people in another house. A given person should estimate a 1/3 chance that they're in the first house - and the fact that 1 house is half of 2 houses is completely irrelevant. Why should this reasoning be any different just because we're talking about possible universes rather than houses?
The axis lines on the probability chart seem broken - there are <0 and >1 probabilities.