Sister battles

Talia
I'm 20 and my little sister is 17. She has a smaller bedroom than I right now and in 2 weeks I'm moving away to college for the first time (I've been going to community college for the past 2 years). My little sister staked out a claim on my room after I leave 3 months ago and incessively nagged my mom about it and my mom agreed. And for a while I wasn't really sure what to make of this but I was like okay I guess makes sense because I'll be leaving
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Now time is cracking down and I have to finish packing. And I'm looking around my room today and thinking, where am I going to put all this stuff outside of my room so my little sister can move in? Where am I going to put all my stuff from college when I move back for the summer? And then my little sister and I started fighting about it because I was trying to make my argument that she shouldn't move in here and she insisted she should because she's always had the slightly smaller room.
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But seriously though?? What am I supposed to do with my stuff?? For college after a year I'm planning on looking for my own place. But with my dresser, tables, drawers, bed, big trash can in my room that I can't take with my to college my little sister says she'll just move her stuff in there too. And I'm like NO these are my things, they are part of my stuff. 
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I know this post sounds really young but this is so SO much more stressful with my move to college. It would be so much easier if my room were kept as is so that moving things out and in would be a easy transition. Anyone agree or have thoughts to share? 
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Edit: No I don't have a baby. And I can't move my stuff into her room. She has not made any effort to pack up her stuff. Her plan is for me to pack up all my stuff I can take with me, and then while I'm gone take her sweet time moving her stuff across the hall down into mine. Including using my dresser, tables, big/small room things I can't take with me. And the thing about that is in my house if someone has been using something for a while, it pretty much becomes "theirs". So if my little sister is using my stuff after I leave, it pretty much becomes hers. So I lose everything I have to leave behind that is furniture and what not!