My sister is 13 years younger than I am. I moved out when I was 18 and she was 5. I was the oldest, she was the youngest. And she was the spoiled brat!!!

We had very little contact though the years. She had her life, I had mine. I moved from Michigan to Ohio and then to South Carolina.

After 46 years, she moved to my town. We found we are a lot alike and are now best friends

Never thought that would happen.

Your room should be off limits to her unless you invite her in (and vice versa!).
She should respect you as long as you respect her, too.