I would sit down and talk with your parents and see if you can come up with a solid plan for what you will do when you go away to college in two years. Don't look at "I'll sell her" as the easy answer because, as we all know, the market may not support that even two years from now. I am a big fan of having a Plan B, and C.....and maybe even D....before I commit to things. IF you come up with a good solid plan and are able to afford having a horse of your own (remember to plan for things beyond the basics of board/feed -- routine care, emergency care, etc need to be given due consideration), why not.
Talk with the BO about your concern for the future. You may be able to work a deal with them to help you as a leasing agent or to purchase her back if/when the time comes that you are unable to take her with you.