How do I prevent my 16 year old daughter from caving in to peer pressure?

My 16 year old daughter is wonderful. She is involved in so many activities and is not your typical teenager. She is so open with me and tells me everything. She doesn't drink, smoke, or have with guys. She really has so much going for her and seems so way ahead of typical teenagers with regards to maturity and common sense. However she's been second guessing herself lately. It seems that all of the other teenagers are always drinking, smoking and having as a pastime. Being surrounded by this and having all of the other teenagers criticizing her and being condescending towards her about it, is making her have some doubts. How to I keep her on the right path? I try to reure her that her lifestyle will pay off in the long term but she's wondering if maybe I'm being too rigid and old fashioned.