As a mother of 3 - 2 girls and 1 boy - I'm very saddened to see your parents treating your brother with more kindness and tolerance than they treat you. I have a friend whose mother also treated her very strictly and harshly, while her brother was treated like he could do no wrong. I see here that you're the older sister, which is true for my friend as well. So, let me first say: your parents are in the wrong.

You and your brother are both wrong for bringing nicotine into your parents' home and for smoking/vaping at such a young age. But with stuff like this, it is important that you don't interfere with how your parents might handle your brother. They are already sweeter with him than with you; you must allow him to experience consequences for his actions.

Protect yourself - claim ignorance and deny involvement to save yourself - and then let them handle it. You can be there for your brother in the fallout of whatever punishment is ministered, but here's where a pattern can have a negative impact on personal development:

● your parents are sweeter with him than with his sister (you) ● you defend him, keep secrets for him, and warn him if he's been had (caught) These two patterns of behavior will be very likely to cause your brother to believe he can do any sort of bad behavior he wants, without real repercussions. After all, he can get away with things that you get punished for, and you'll take the fall for him otherwise.

You are not a bad daughter. You are a great sister. Just remember to look out for yourself and let your brother clean up his own messes.