Is it possible to get custody of my non-blood related grandchild who is fifteen years old if the grandma who has tried to commit suicide several time and has made threats of suicide serveral more times.we are going through a divorce right now because of this and I don't feel safe with her having custody of my grandaughter.I have raised her since she was three years old as my own child?If so can I also adopt the same said child if she wants me to?

Probably... it depends on where you live in.
If you are in Tn-you are out of luck.