First, you should be very proud of your daughter for this milestone for your family. Congratulations!
Second, you are very wise to be aware of the type of peer pressure that might be a negative factor as your daughter moves onto college.
My advice is simple- constantly reinforce her decision to go to college, explain that a college degree is a requirement in the future to obtain a good job, and continue to tell her how proud you/family are for her decision.
Positive reinforcement is a key way to help youngsters deal with peer pressure.
I think it's great that your daughter is going to college. I 'm a first generation college student myself. Without anyone in your family going to college before you gets overwellming because you have no one to turn to advice. If she is having doubts about college due to her friends staying behind, I would suggest trying a local community college first. All her credits will transfer to a 4 year school.