I would tell 17-year-olds to be proud of who you are. Don't try to change yourself for others. Focus on school and your future. Boys and friends will come and go just focus on you and your future.
I look forward to a time in the not so distant future when we no longer look forward to 'firsts' as milestones women have yet to achieve but we look back on them as historic events that continue to teach and inspire.