I have a problem with my older sister. She keeps taking my stuff...

..and then she ll throw it into the trash, sell it, or lock it in her trunk. She's reaching 30 and still lives at home. I share a room with her, which makes it easy access to steal.. You would think that at her age, she wouldn't be acting like a little immature kid. And I already confronted her in a mature way about her stealing habit, but that didn't even work. I have most of my stuff locked up, but she will steal literally anything; and the bedroom will look like a empty spot on my side,.. if I have to lock up my pics, posters, blankets, pillows, ect. Does anyone have advice on how to deal with her?

Wow, that sounds awful to deal with! I don't know how old you are, so I don't know how much longer you're looking at living with your parent(s) (I'm assuming that's where you live.)

I'm guessing you've already talked to your parent(s) about this?

All I can think of to do is to get something large that you can lock to keep your things in when you're not there.

Hugs.

I wonder if she is suffering from a mental illness.