@ 17 years old peer pressure is no joke, kids are becoming young adults and in school all the cool kids are experimenting with alcohol, drugs and sex. The need to be accepted is very high. Try to understand times have changed. I believe the worst way u can react is to physically or verbally attack her. Please reason with her in a calm manner and try to be in her life more often, perhaps hanging out with her during weekends doing family stuff. It's also very important that u treat her like an adult by letting her make choices and mistakes that she can learn from.