My classmate (12) vapes and literally no one seems to care about it

For starters, I'm 13, we're in 7th grade and her birthday is just a few months away. She shares images of her vaping to LITERALLY everyone and barely tries to hide it. None of my classmates seem to let this affect their view of her except for a few. The thing is, if we were 16 or something, I'd understand. But we're 7th graders, genuinely, what is it with everyone trying to grow up so quickly?

However, vaping/smoking could of course be her way of coping with a mental health issue. I am not fully aware of her mental state, but from what she has told, she might struggle with certain mental health problems. For many people, doing such things is a way to distract themselves from their worries and problems, which could be the case for her. 

I'd definitely let that slide, but the way that she acts so proud of her actions and doesn't even try to show some kind of shame makes me doubt it. Also, she's extremely disrespectful to people that actually struggle with mental health. She mocks depressed people, people who do self harm and such. And then she DARES to repost things on tiktok with "#anxiety". I know reposts aren't that serious, but there's already so many things about her that piss me off. And it's also full of stuff like "maybe if you were to actually get to know me, you would've known how different I am." And if you actually get to know her, she's not any different at all??? The way she acts with her close friends is barely different than how she acts with someone like me.

I got this info from another friend of mine (she was describing her experience)

Basically, they were on call with the classmate that vapes, and another friend of mine. The classmate that vapes turned her camera on to show multiple vapes and packets of snus, while saying "Shit's about to go down!!"

The thing is, me and her have a looooooong history of beef. When she first moved into our class (2nd-3rd grade) she was extremely annoying and whenever I called her out on it, she'd say "Haha, I know! I'm the most annoying person in the whole world XD!!" Back then, I had a shit ton of anger issues so she'd always purposefully say things that she KNEW would make me sad, but it was years ago so I don't let it affect me so much. 

She was SO insanely aggressive to her friends and everyone, it pissed me off a lot. Like, these kids were literally tearing up?? One day, I genuinely couldn't stand watching her do that shit because I've always been a person that advocated for "justice" (even though it wasn't that serious in this situation. And so, I grabbed her by the braids that she always wore and kinda dragged her like that one clip from Matilda. We exchanged a few slaps, and then the teachers made us go outside to make up.

She said that the reason she was so aggressive, and this is WORD FOR WORD, was because "she grew up around boys!!" 

That was like in 4th grade, so it's not so relevant, but also a part of the reason that I dislike her so much.

She also makes one of my friends extremely uncomfortable, as this friend has clearly shown signs of hating physical affection, and also disliking HER too, she does things like kiss this friend's cheek, hug, and just more. She says that kissing people is her way of expressing love.

She also makes inappropriate jokes about one of my friends, while said friend is in a sapphic relationship.

And I still just don't get it how she's still SO popular. Everyone has seem to have forgotten how old we are. Like, sometimes I feel like I'm the only person here that ACTUALLY acts like a 7th grader.