I didn’t think it through that she was your student. Yeah I’d say it’s inappropriate. If you met her in the situation where you both on equal footing like both playing in the amateur same sport team or community art class then maybe it would be ok

It also depends where is she in life. If you are both college students it’s one thing. If she is in high school and you are independent adult, it’s just wrong.

Also be aware of her parents. Even if she is 18 (unless you saw her documents you just don’t know), her parents sent her to camp, paid for it, and hoped she received good care. They sure would be unhappy to find out that instructors ask her out (even if class is over) or that instructors discuss how she’s supposedly attracted to them because she is approaching them privately. As a parent I’d be very unhappy.

Just meet women in other places even if they are younger than you.