Become her boyfriend, start living together, put her in a cage in the basement with a man-sized hamster wheel for exercise and a faucet for water. Only let her stream under supervision and reward a good stream with food. Take her on a date once a month to keep the menhera away.
Take it from someone that's actually had to teach their partner how to detach herself from social media, it's much harder than this. Zoomers live to dox themselves and everyone around them, it's only through overwhelming autism and the ability to demonstrate why it's bad if someone can triangulate your position from an instagram feed that they can be swayed into stopping.
Do your oshi a real favour and do the same for her by gangstalking her to the brink of insanity so she'll understand.
Also, how old is Hexa? Mid-lateish 20's? Wouldn't that mean she's like 14~16 in these videos? Sure nothing weird with posting teenage girls dancing.