younger sibling vaping -- what to do?

hey, ive suspected my younger sister has been vaping the past few days-- id go to the bathroom after her and it would smell oddly sweet, i'd ask and she'd say it was gum, sweets, perfume. i bought it kind-of, i straight up asked if she was vaping and she said no.
but earlier today i went to our room and the air was all vapour, smelled sweet, and she was ******* spraying perfume as if that'd stop me noticing 💀
again, i asked if she was vaping. she gave me this withering look as if i'm the crazy one here and said no.
so what do i do? she is defo vaping, and she's underage-- only 15. should i tell my parents?
i dont even know where she's getting the money and where she's buying them... i'm mostly ****ed about how she's barefaced lying to me about something insanely obvious.
do i leave it be?? i don't know of the health risks with vaping really, if there is any? i've smoked but not much-- but i'm of age, and she isn't. and she doesn't know so i couldn't have influenced her here... advice??

I would tell your parents - this is an issue that they should deal with. Unfortunately, when you try to confront siblings about this kind of stuff they don’t tend to listen to you but if your parents talk to her then she’ll be more receptive. And there are plenty of health risks associated with vaping (not as many as smoking but it’s still harmful), especially since she’s still young.
What your sister is going to struggle with is stopping (because of the nicotine in vapes). I’ve had to deal with something similar with my sibling before and the things that I found was that my sibling needed to be confronted by someone they trust most (parents) but still needed someone who didn’t talk to them about their issue and was just a shoulder to lean on (myself). I would recommend not explicitly telling your parents that your sister is vaping but guiding them towards the realisation - that way your parents can confront her with their own evidence and you remain someone who is outside of the situation so you can give your sister support by being someone she can talk to without feeling judged. Addiction is really difficult to deal with so this is going to be really hard for your sister - she’s going to need both confrontation and support.

thank you! i have 0 subtelty so i told my mum straight-up, and my sister eventually admitted to it and handed in the vape.
it turns out my sister bought it from a vape shop, and they didn't ask for her ID. i have no idea why she bought it.
i think my mum is going to complain to the local council about it because she looks her age and they sold it no problem.
thanks all for the advice.

That’s great! Glad it worked out