So I have a bunch of home automation projects I've been tinkering with weather related. One of which is an air quality sensor that determines when the air quality is bad with the intention of displaying some visual notifications around the house. I've been working on the coding for it and currently have it sitting on my desk in my home office. My most recent addition to it was having it graphing the data out to a webpage on my home network so I could see the change over time. The day I finished it and started testing was the day before Thanksgiving, my niece, 14 years old, decided she wanted to spend the night to hang out with her cousin, my son, since her mom and dad were coming over for Thanksgiving the next day anyways.
My home office is also our guest room, so the bed she sleeps in is in there. She went to bed about 10, I went downstairs to play some video games and have a couple of beers. I finally went to bed about 1 am, when I walked passed her room, I could hear her talking on the phone.
Next morning comes and after everyone is up and moving I decided to check on my air quality sensor and see how the data looked on the graph. As soon as I pulled up, something was really suspicious. It was basically a flat line with values between 1 and 5 most of the time, but at 1:05 am and 1:15 am it spiked twice to ~150. I took me a few seconds to put 1 and 1 together... "the only time I've ever seen it get that high was when food was cooking and there was smoke coming off the stove"..... ohhhhhhhhhh.
I called her into the room and showed her the paper and told her, "The only reason these numbers would show like this is there was some kind of smoke in the room". She said, "I don't smoke". I said, "Or something like a vape pen." Her face went white, "Are you going to tell my mom?" "No, but you need to give me the vape pen". So now I have a vape pen.
Stop being her friend and be an adult. Give the vape pen to her mom and explain the circumstances and let mom decide what, if anything, to do. At 14 she has no business vaping and you might just save her long term lung damage.
Not everyone has a great home life, and there are absolutely situations where the right answer, even for stuff that's quite serious, is to not say a word to the parents.
And that's ignoring the point everyone else is making regarding having someone that the kid trusts, so that when they screw up badly, they have someone that they are willing to call or tell about it, instead of trying to hide it from everyone, letting stuff get much, much worse.
A whole lot of this can be summed up like this: Sometimes, there are no good answers, and you only have the choice of different kinds and degrees of bad ones.
In this case, I think OP made exactly the right call.
Can she get another vape pen? I mean, let's be honest, she probably already has.
But now she knows that if she gets into a much worse situation, she has an adult who is both willing to call her on stuff, and who isn't going to do something to make it worse.
She's 14, that's both old and young enough to do stuff with people that she's not supposed to, in places that she's not supposed to be, and for it to turn into something bad in a hurry.