Go ahead and take a moment to give yourself a nice pat on the back. Sounds like you have raised two wonderful children!
Reading the post made me think of my niece who is now 18, but also sounds a lot like your daughter being that she was shy growing up. During her freshman year in high school she decided to join JROTC and told me it was because I served in the Air Force. It surprised us all that she made the decision on her own as high school was a tough transition for her due to her stuttering communication disorder.
Getting involved in that program at school did her wonders and she blossomed right before everyone's eyes. So much so that she ended up singing the national anthem in front of the entire school, which ended with everyone giving her a standing ovation. Thank you for reminding me of that sweet memory and I hope that you will always carry yours with you forever.