As an older brother to a now-20-year-old young woman, I can relate to a lot of what you wrote. And it's only going to get worse from there. Worse and better. She will always be the "little sister" on some level, but watching someone who you've literally known since birth grow into a mature, fully realized human being is an amazing experience. Amazing and humbling.

It sounds like you were a good big brother to her. You have a lot to be proud of.