Oh (((skittles))) I'm sorry to hear all this you and your mom are going through. Keep all the records of the ssi requests and copies of the applications etc... it will be retroactive once she is approved.
There is a lot of documentation regarding fibromyalgia. Make sure your attorney is on top of this.
Chronic pain causes depression. Even if she was depressed prior to the fibromyalgia being dx'd, she should still go to a psychologist who specializes in pain management... they can help immensely. (I see one, and he keeps me alive through my pain and fatigue and all that stuff.)
It's good that she has you and other family to share with, but that is a huge burden on you...and she really does need a professional who can help her progress. Someone who will, with expertise, validate her over and over regarding what she is experiencing.
Sky