Relationship Advice

Ali
Okay, so my girlfriend and I have been together for almost a year now. We're both seniors in High School (yes, I know we're young). I plan on going to college to become an Anesthesiologist or Oncologist and (not to brag or anything, I Swear) I'm a very intelligent person. I've gotten all As and Bs since I've been in school and I'm very skilled in Math and Science. My girlfriend, on the other hand, doesn't know what she wants to do and she's not stupid, but she isn't at the same intellengece level as me, if that makes any sense.
So here's the main problem: my family is worried that because of the difference between us, intellectually, I'm going to be unhappy if I chose to spend the rest of my life with her. I love her so much, she's an amazing woman and treats me so well. The chemistry that we have together is unlike anything I've ever experienced before and she's told me the same. So I'm not unhappy, but they fear that in the long run, I will be. We can talk and talk and talk forever and we love almost all of the same stuff. But I can't help but feel worried that when the times for me to go off to school and move on with my life, I'll become unhappy. 
Please help me..any advice is welcome. I love her so freaking much and I can't bear the thought of losing her. Again, I know that we're both so young and I shouldn't get my hopes up(I've heard this MANY times), but she's someone that I feel I could have a future with. I'd really LIKE to have a future with her. Please help.