My sister hasn't always been the most responsible person and tends to be very self-centered, but I knew not having her in my wedding would cause a lot of drama. However, having her in the wedding has also caused a lot of drama. I just got off the phone with my mom and my sister apparently she wore her bridesmaid dress to a wedding over the weekend and she got wine on it. My sister told my mom she tried to get the stain out, but nothing has worked so far. She asked my mom to tell me because she was worried I would lecture her for wearing the dress before my wedding and she didn't feel like being lectured because she already feels bad. My mom purchased the dress for my sister because she said she didn't have the money to buy it. I don't know what to do at this point because I know my sister will throw a fit if I ask her just to attend as a guest or that's what I would do. I am already paying for my sister to have her hair and makeup done because she through a fit because she would be the only girl not having hers done because she couldn't afford it so I decided to cover the cost. Any advice?