How do i help a family member that has depression?

Hey everyone, so my 16 year old cousin has been diagnosed with depression. Why i have no idea, but i would like to help her. She is very bright and i would definitely not want to see her go through this. I do not understand why she has depression. She IS one to brag about everything she wants and has and will get so people don't really like her because of it. Maybe it could be a reason why. We went to the same school for a while and she was just alone all the time, her friends stopped talking to her and she always pretended to be on the phone even when she was not talking to anyone.. Which everyone saw as weird. I tried to MAKE her hang out with my friends and i but she would distance herself. I got to notice that what she does is try to get attention by talking and bragging about material stuff ad people just got fed up with it and stopped talking to her. So can someone tell me how i can help her??? She is now in a clinic because she cut herself and even went as far as seeing people that were not there..(her dad and step mom "laughing" at her) maybe she has problems??...  My aunt has been told that she has the highest level of it.. Don't know what it is called or anything.. Please help, all answers will be appreciated...

[crayonchewer]

She brags because she feels something that makes her happy.
she talks on th phone maybe because she wishes to have other feel envious or wishes to have friends.However she don't realy want friends probly for fear of being hurt or just feels safer alone.
If my family laughed at my problems I'd be pretty upset too:/
Maybe she'll be ok though, depression is common in teens these days.

[jreyna49]

yeah i have noticed that, she is about to be back from the clinic and well im still looking on stuff i can learn so i can know how to help her better