Mental health concern?

My cousin seems sad and unhappy all the time and does not have many friends.Niether does she make efforts to make new friends.She seems content the way she is and usually is ok if she has one close friend.Even with that friend she does not interact too much - just when she needs to.She is mostly self absorbed and lost at times.She also likes to sleep and lacks zest and zeal in life.She also think about eating all the time and seems to be highly ytical about everything she consumes.She is not gaining weight though.Is something wrong with her ?