Want to live on my sorority floor but don’t know how to tell my roommate.

So at my uni we don’t have sorority houses we have floors in the dorm. I want to live on mine and plus it’s a $600 fine if you don’t your second year, I like my roommate but I know she wouldn’t live on the floor with me plus we have our suite mates and everything. I don’t want to leave her with a random because she knows nobody else to room with and I would feel bad. I don’t know what to do any advice?