My sister got married on Friday at a court house. Over the past few weeks she has treated everyone in my family horribly. She has told us she hates us and wants nothing to do with us ever again. She deleted everyone on Facebook except for my husband. She didn't even tell us she got engaged and my mom found out from a friend of hers because my sister posted it on Facebook and my mom's friend messaged her telling her that my sister was engaged. She also accused our parents of favoritism and child abuse. She feels she was abused as a child because she was grounded. She happened to be grounded more than my brother or me which is why she thinks they favor us. She seems to forget that she behaved worse than either of us. A few days prior to the wedding, she messaged my mom demanding money in cash because they parents bought my wedding dress. My brother also works for my parents so all of the money he was paid by them while he was working went towards the wedding, but she feels she is entitled to that same amount of money in cash as well. My parents had previously made payments towards her first wedding, but she ended up cancelling that wedding. She was refunded some of the money our parents paid, but she kept it. They offered to buy her a wedding dress, but since she was getting married at the court house she didn't want/need a wedding dress. She just wanted them to give her thousands of dollars in cash because she feels she is entitled to it. My parents said no to handing over a lump sum of cash because they don't trust her or her husband to spend it wisely because they both have a history of drug abuse. After my parents said no, my sister called them about every name under the sun. As of this morning, she texted my grandmother telling her they are now accepting wedding presents. After everything she has said and done, we don't feel she should be expecting anything from any of us. Do you think we are wrong or how would you handle this?