Is my sister suffering with a disorder?

Hi.  I'm reaching out for help to see if anyone out there is dealing with a similar situation.  My younger sister is the most angry, hateful person I have ever known.  She is now 39 years old and feels that everyone owes her an apology for something or another.  She's blames my parents for not being there for her when she was younger.  She claims they forgot her 16th birthday which I know for a fact is not true.  She blames all of us because she didn't have the big white wedding.  She got pregnant while in college and got married in a small chapel with just our family.  We had a reception back at my apratment after; it was very nice.  She just can't get over the fact that all of her sisters had a large wedding and she didn't.  She now claims that she's not married and won't be until her husband proposes to her and gives her the big white wedding she deserves.  Her kids have to live with this day in and day out and let me tell you it's no picnic.  The world revolves around her and she puts herself before her kids.  Very negative and always unhappy.  She looks for things to complain about and loves to bring up old memories that weren't so happy.  She always sick, something is always wrong.  Whenever we have a get together, she shows up fanning herself to the extreme so that everyone will notice and when someone asks how she is she says she needs to take her medication right away or someone might have to call 911.  It seems to me that she should have done this before leaving the house so that she wouldn't have to worry about it.  It's the same old thing everytime.  If the event is about her like a birthday or her graduation party, she is so happy and has no complaints about being sick and loves all of the attention.  Some of you may read this and think its nuts and it is.  At the moment she won't have anything to do with me because I collected some tables that I loaned her and she says that those tables mean more to me that her or her kids and now I owe her an apology.  I'm lost.  I love my sister but I hate being around her.  It's hurts me when she says things that are so mean.  She always takes a stab at someone to be noticed I guess?  She works for a law enforcement agency and told my boyfriend that if he ever crossed her that she could make sure he would wake up with a criminal record.  This is when I finally had enough.  I'm really afraid that there will be physical fighting if I don't find out how to handle this situation.  She has been told by several family members that she needs to see a psychiatrist but she says that she is the only normal one in the family.  Is there anyone out there who might be familiar with this type of behavior and if so what should my family do about it?

[tinkerbell1124]

I'm NOT really sure what you can do about it!!! BUT it does sound like she has some mental issues going on. Sorry you have to put up with that!!!!