Answer: it seams that your parents expect you to follow their rules since you live under their roof.
Step-by-step explanation:
This is because, she lives with her parents, so there are certain rules being set by her parents, one of those rules being set is not taking of alcohol. Since she lives under the same roof with her parents, she is expected to abide by those rules. So her friends visiting her would not be able to take alcohol since she still lives with her parents, the rules of her parents prohibit the taking of alcohol.