I think regarding sex stuff... Context might help.
My family is Muslim, and my mom absolutely would not let my younger sister have a boyfriend. When I was my sisters age, my mom completely avoided talking to me about sex. My older sister is also not a nice person, and I know my younger sister and her basically don't get along.
So knowing all this, I worry that my sister, now being left alone for three weeks, is going to do what probably a lot of kids will do at her age. Rebel. But I'm not confident that she's had any talk with my mom or sister regarding sex other than "don't, or else". I really don't want these three weeks to be bad, I don't want her getting pregnant or getting an STD or any shit like that.