AITA for not sharing my 700 dollar purse with my sister as her wedding dress for her wedding tomorrow?

I have a little sister, she is 22 and I am 25. We do not have the best relationship but it is fine. I have a job, she is in school. Our parents do not give her money for anything other than her schooling and I have to pay for anything else she needs. <br><br>This includes her wedding, which is tomorrow. She got pregnant unexpectedly and her fiance asked her to marry him. She said yes, and then told everyone else. Our parents are not happy because they wanted her to finish school first, especially since they were paying for a lot of it. <br><br>My sister went all out for her wedding. She bought a really expensive dress, the jewelry, the decorations, the food, the DJ, the venue. She spent all of her savings and is thousands of dollars in debt. My fiance and I are paying for some of it but she bought a lot of stuff without consulting us first. <br><br>She knows our budget is tight but she kept saying she had things under control. She did not have things under control. We sat down and talked with her and told her that a lot of the things she was gonna have were not gonna happen. <br><br>She was not happy but understood. She then asked me if she could wear my purse. It's a really pretty purse from a high end brand and very expensive, it was a gift. She loved it since the first day she saw it. I told her no. <br><br>She asked why and I told her that even if I was gonna wear it to her wedding, which I am not, I just have a small purse with a flower on it, it is too small to be used as a dress and on top of that it was not hers. <br><br>She asked me if I could just let her borrow it and I said no. She then asked me if I could sell it to her. I told her I had no interest in selling it. She told me I was being a bitch. I agreed we were not the closest but I did not think I was being a bitch by not letting her use my purse like it was a handkerchief or something because she had no money left for her wedding dress.