Once you get into college and everyone is smarter than you in so many different ways you won't worry so much about being overshadowed academically. People all have strengths and weaknesses, if she's better than you at some things she's probably worse than you at other things. (My brother has a PhD from Caltech. But I'll always be better than him at NetHack!
) And in high school it may look like there's a linear progression of "smartness," but really intelligence doesn't matter that much, and there's kind of room for everyone to fit into the world even if they're not so smart or didn't get such good grades...like in research, the top authorities aren't the most brilliant scientists, they're just people who've worked on the same problem their whole lives. And there are many different problems to work on, so lots of room for both you and your sister to thrive...
In other words, it'll get better. Cheer up
