AITA for getting my sister fired after she stole my birthday dress?

I am 19(F) and I have a younger sister, Summer who is 18(F) My sister and I have never gotten along. We are complete opposites. Like while I love math and science, my sister loves Arts and Crafts and anything creative so we never had a common ground to talk about and we never really cared for each other. My parents have tried to get us to be close and have us do things together but it always ends in an argument. Our birthday's are only a couple of days apart so our parents have always wanted us to have a shared birthday party. I have always dissented but my parents felt that since we are so close in age, we should "appreciate the other one" AND it would be cheaper. I get that it would be cheaper but it's my birthday too and I wanted to have my own celebration.<br><br>This year I turned 19 and my parents were still set on us having a shared birthday party. I argued with them that my sister and I do not get along so why would we want to celebrate together? They thought it would be better if we had our own birthday party (with the same theme) so my sister had a disney theme and I had a Harry Potter theme. The theme didn't really matter since the party was for both of us. I was still dissatisfied that I didn't get to have my own party and I was right to feel that way because my sister kept trying to change my theme to the same theme as hers.<br><br>My sister got a new job at a costume shop a couple of months ago. She was really excited and she was telling us about all the cool costumes she'd seen and how she'd love to were some of them. My parents suggested that my sister get me a costume and I wasn't too excited but I said fine. She went all out and she did a very good job on my costume. It was a Hermione costume and it looked amazing. She also made a costume for herself. She made Belle's dress which also looked amazing.<br><br>She took her costume and wore it to work for the next couple of weeks and I never said anything I just felt like it was weird that she kept wearing my gift that I never wore or even planned on wearing. She also didn't ask me for permission so I felt disrespected. A couple of days ago my friend suggested that it was my birthday and I should wear my costume to celebrate. I hadn't worn it since my party so I agreed and I went to get it but my sister had taken it to wear to work. I cussed at her and I yelled at her. My parents scolded me and told me to apologize. I told them that she is the one who should be apologizing. My dad said that I should drop it and move on.<br><br>The next day I went to pick it up and she said she couldn't take it off yet because her boss liked it and he wanted her to wear it for the rest of the week. I wasn't okay with that but she said that her job was more important. I told her that I'm wearing it this weekend and I'm coming to pick it up tomorrow and she agreed. I went to pick it up and all I saw was the Belle costume. I asked when she was going to bring mine back and she said that she couldn't because her boss had bought it and he planned on using it for a show he was putting on. I got angry and I took the Belle dress which was hers and I got ready to leave. She told me not to take it. I told her that if she didn't return my dress I was taking hers. She said that she was calling the police and I told her to go ahead. She called them and when they came I told them that I was taking something that was rightfully mine back and that if she returned my dress I would give hers back. The police said that technically it was stealing since I didn't steal anything that was hers, only something that belonged to me so they took my sister in.<br><br>She called me from jail and yelled at me. I told her again that if she got my dress back for me I would give hers back. She told me that she couldn't get it back and the boss sold it. I told her "okay" and hung up. She got fired from her job because of this and she has to pay a fine. I got the Belle dress dry cleaned and it's in my closet. I still have the Harry Potter costume but the beautiful dress that my sister made is gone. Now my parents are mad at me for both getting my sister arrested and fired and for accepting her job as more important than the dress.<br><br>AITA for getting my sister in trouble with the law and getting her fired from her job for stealing my birthday dress?