First, there’s no guarantee you’ll have a room with your sister. Don’t tell your parents, but just because you request a roommate, you may not end up with that person.At some universities, it’s a complete lottery. At others, they look into your habits (if that’s what they use at your university, just make sure to indicate different habits than your sister’s. Only thing you can’t triffle with is whether you’re a morning person or not, because if yu say you’re a morning person and you’re not for real, how do you deal with a ROTC roommate who gets up at 5:30 am? :p)
Also, what sort of dorm are you talking about? Most dorms are one room, with two desks, two beds, etc, and the students share the same room - they don’t have an apartment with two rooms in it. The “pods” or “suites” that you liked tend to have, indeed, 4 rooms for 4 people although some have 2 rooms for 4 people who share a bathroom.
Have you visited the university yet? Spent an overnight there? If not, you should make a request ASAP.
Have you applied to the Honors college? If it’s by invitation or you need to have specific stats, are you near their typical profile? If so, do apply.
Your sister is probably as unhappy about this as you are. But it’s WAY better to be living on campus than to be commuting, even if you live with your sister. You just make sure to have a packed schedule 